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                         NGV ECOTRANS TECHNOLOGY CENTER




                  NATURAL GAS VEHICLE DEVELOPMENT COMPANY INC.

                                       AND

                        ECOTRANS AFTERMARKET CORPORATION

                                        A

                                  JOINT VENTURE





                                   MAY 1, 1993


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                             JOINT VENTURE AGREEMENT
                                      INDEX

                                                                         Page
                                                                         ----
 1.   Definitions                                                          1
 2.   The Joint Venture                                                    4
 3.   Contributions by Parties                                             9
 4.   Interests and Undertakings of Parties                               10
 5.   Management Committee                                                12
 6.   Manager                                                             14
 7.   Programs and Budgets                                                17
 8.   Accounts and Settlements                                            18
 9.   Distribution and Allocation of Income and Loss                      20
10.   Insurance                                                           21
11.   Representations and Warranties                                      22
12.   Parties' Defaults and Remedies:
       Arbitration of Disputes                                            23
13.   Indemnification                                                     25
14.   Termination                                                         26
15.   Transfer of Interest                                                27
16.   General Provisions                                                  29

      Exhibit "A"     1993 and 1994 Budget
      Exhibit "B"     Cylinder Pricing Schedule
      Exhibit "C"     Tax Matters
      Exhibit "D"     Schedule of Equity Contributions




                             JOINT VENTURE AGREEMENT

     THIS AGREEMENT is made as of the 1st day of May 1993 (the "Effective Date")
by and between Natural Gas Vehicle Development Company Inc., a California
corporation ("NGVD") and EcoTrans Aftermarket Corporation, a California
corporation ("ECA"). The parties hereby agree to form a Joint Venture upon the
terms and conditions set forth in this Agreement.

                                    RECITALS

     Whereas, NGVD and ECA wish to enter into a Joint Venture for certain
business, technical, and public interest purposes with its primary goal being to
generate a profit by providing superior equipment and services necessary to
contribute to the development of a credible natural gas vehicle market.

     NOW, THEREFORE, in consideration of the covenants and agreements contained
in this Agreement, NGVD and ECA agree as follows:

                                    ARTICLE I

                                   DEFINITIONS

     1.1 Intentionally omitted.

     1.2 "Affiliate" means any person or entity related to a Party in such a way
that either the Party or such person or entity directly or indirectly controls
or is controlled by or is under common control with the other. For this purpose,
"control" means the power, direct or indirect, to direct or cause direction of
management and policies through ownership of voting securities, contract, voting
trust or otherwise.


                                        1


     1.3 "Agreement" means this Joint Venture Agreement, as it may be amended
from time to time, together with all exhibits to it.

     1.4 "Assets" means all real and personal property of the Joint Venture,
tangible and intangible, transferred to, held, developed or acquired for the
benefit of the Joint Venture.

     1.5 "Authorized Person" means the officers, directors, principals and
employees of a Party and its Affiliates whom a party designates as an Authorized
Person by notification to the Management Committee.

     1.6 "Budget" means a detailed estimate of all costs to be incurred by the
Joint Venture with respect to a Program and a schedule of cash advances to be
made.

     1.7 "Change in Control" means the occurrence, in the case of a corporation,
of any Person becoming the beneficial owner, directly or indirectly, through a
purchase, merger or other acquisition transaction or series of transactions, of
shares of capital stock of the corporation entitling such person to exercise
greater than 50% of the total voting power of all shares of capital stock of the
corporation entitled to vote in the election of directors.

     1.8 "CNG Cylinders" means compressed natural gas cylinders which are
manufactured by CNG Cylinder Company a division of NGV Systems, Inc., a Delaware
corporation with offices at 2250 Cherry Industrial Circle, Long Beach,
California 90805.

     1.9 "Contract Year" means the period from the Effective Date through
December 31, 1993 for the first Contract Year, and the calendar year (January 1
- - December 31) for each subsequent year.

     1.10 "Defaulting Party" shall have the meaning set forth in section 12.1

     1.11 "Effective Date" means the date this Agreement is set forth by the
Parties, as shown in the initial paragraph of this Agreement.

     1.12 "Equity Contribution" means the contributions which each Party agrees
to make to the Joint Venture pursuant to Article III of this Agreement.

     1.13 "Insolvent Party" shall have the meaning ascribed to it in Section
15.5.

     1.14 "Internal Revenue Code" means the United States Internal Revenue Code
of 1986, as amended from time to time.

     1.15 "Joint Venture" means that entity created by this Agreement.

     1.16 "Joint Venture Financing" means financing arranged by the Joint
Venture to fund approved Budgets and Programs.


                                       2


     1.17 "NGV Conversion Kit" means the components and apparatus required to
convert a gasoline or diesel engine to enable it to be fueled by natural gas.

     1.18 "Management Committee" means the committee established under Article 
V. 

     1.19 "Manager" means the person appointed pursuant to Article VI.

     1.20 "NGV" means Natural Gas Fueled Vehicle.

     1.21 "NGVD" means Natural Gas Vehicle Development Company Inc., a
California corporation with an office at 2250 Cherry Industrial Circle, Long
Beach, California 90805.

     1.22 "Non-Defaulting Party" shall have the meaning set forth in Section 
12.1.

     1.23 "Notice of Default" shall have the meanings set forth in Section 12.2,
as the context requires.

     1.24 "Notices" shall have the meaning set forth in Section 16.1.

     1.25 "Operations" means the activities carried out under this Agreement in
accordance with approved Programs and Budgets.

     1.26 "Participating Interests" means the respective percentage ownership
interest of a Party in the Joint Venture.

     1.27 "Party" or "Parties" means the persons or entities that from time to
own participating interests.

     1.28 "Person" means an individual, a partnership, a corporation or any
other legal entity.

     1.29 "Program" means a description in reasonable detail of Operations to be
conducted by the Joint Venture for a designated period, which is adopted by the
Management Committee under Article VII.

     1.30 "ECA" means EcoTrans Aftermarket Corporation, a California Corporation
with its principal office at 555 West Fifth Street, Los Angeles, California
90013-1011.

     1.31 "Tax Matters Partner" shall have the meaning set forth in Exhibit "C"
which is attached to this Agreement.


                                       3


                                   ARTICLE II

                                THE JOINT VENTURE

     2.1 Formation. NGVD and ECA hereby enter into and form a Joint Venture,
which shall be a general partnership under the laws of the State of California
for the limited purposes set forth in this Agreement. The Assets shall be held
in the Joint Venture name and not in the names of the individual Parties, and no
Party shall have any individual ownership in such property except for its
property rights as a Party to this Joint Venture. All agreements, permits and
transactions regarding the Assets, shall be executed and performed by the Joint
Venture in its own name and not in the names of the individual Parties. The
Joint Venture shall operate in accordance with the terms and conditions of this
Agreement.

     2.2 Name and Principal Place of Business. The Joint Venture shall conduct
its business under the trade names "NGV EcoTrans Technology Center". Its
principal place of business shall be Los Angeles, California. The principal
place of business may be changed from time to time, and other places of business
may be established by actions taken in accordance with the provisions of this
Agreement governing management of the Joint Venture's business and affairs. The
Joint Venture shall make any registration required by applicable trade name,
assumed name or fictitious name statutes and similar statutes.

     2.3 Purpose. This Joint Venture, a profit oriented business, is formed for
the following limited purposes and to perform any operations or activities
necessary, appropriate or incidental to the conduct of the Joint Venture:

     (1)  Business Purposes.

     (a)  Conversions:

           (i) To undertake the conversion of vehicles to natural gas power;

          (ii) To furnish information concerning, but not to provide, customer
               financing for NGV conversion and equipment costs;

         (iii) To provide quality NGV conversions at reasonable prices and in
               accordance with customers desires;

          (iv) To be the recognized leader within the NGV conversion industry in
               the southwestern United States.


                                       4


     (b)  Testing:

          (i)  To acquire and operate an Environmental Protection Agency/Federal
               Test Procedure ("EPA/FTP") laboratory and emissions testing
               facility for natural gas powered vehicles; and

          (ii) To solicit emissions testing work from underhood equipment
               manufacturers, testing laboratories, original equipment
               manufacturers (OEMs), the Federal Department of Energy, the
               California Air Resources Board, and others.

     (c)  Outside Cylinder and Kit Sales:

          (i)  To be a distributor and stocking warehouse of CNG Cylinders; and

          (ii) To act as a distributor and/or operate a stocking warehouse for
               related parts and equipment that are necessary for operation of
               the NGV business or to ensure availability of such parts and
               equipment to customers of the Joint Venture. 

     (d)  Consultation:

          (i)  To provide consultation, training and maintenance services for
               NGV's and related equipment.

     (2)  Technical Purposes.

     (a)  Promote the establishment of emissions, performance, and safety
          standards for NGV conversions;

     (b)  Develop data base of NGVs' performance including: emissions
          degradation, catalyst performance, lubrication oil degradation, and
          horsepower change;

     (c)  Establish installation quality standards;

     (d)  Evaluate diesel conversion methods;

     (e)  Exchange NGV data with other technical sources; and

     (f)  Provide specification writing capability for conversion projects.


                                       5


     (3)  Public Interest Purposes:

     (a)  Strategy:

           (i) Promote economic advantages of natural gas;

          (ii) Support favorable taxation of natural gas over other fuels;

         (iii) Educate legislators and governmental officials to the benefits
               of natural gas for vehicle operation;

          (iv) Support California Air Resources Board (CARB) vehicle emissions
               standards in the United States for NGV conversion equipment;

           (v) Support tax incentives for clean fuel vehicles;

          (vi) Promote or support other incentives for clean fuel delivery
               vehicles, such as double parking approval or express lane
               permits; and

         (vii) Support federal funding for natural gas fueled transit fleet
               vehicles in California.

     (b)  Implementation: The Joint Ventures' public interest strategy shall be
          developed and implemented only through close coordination with the
          Management Committee. NGVD and ECA shall support and assist with the
          implementation of the Joint Venture's public interest strategy,
          provided however, that the Joint Venture shall not incur any cost of
          implementing the public interest strategy.

     2.4 Powers. In furtherance of the purposes of the Joint Venture as set
forth in Section 2.3 hereof, the Joint Venture shall have the following powers:

     (1) To acquire from other Persons interests in real or personal property of
any kind or description, including, but not limited to leases, licenses,
patents, processes, techniques, machinery, equipment, or contractual rights to
acquire such interests;

     (2) To borrow or otherwise raise money on behalf of the Joint Venture, from
any source, including one or more of the Parties, upon such terms and conditions
as the Management Committee may deem advisable and proper, to execute promissory
notes, drafts, bills of exchange and other instruments and evidences of
indebtedness and to secure the payment thereof by mortgage, pledge or assignment
of or security interest in all or any part of any property or interest then
owned or thereafter acquired by the Joint Venture, and to refinance, recast,
modify or extend any of the obligations of the Joint Venture and the instruments
securing those obligations;


                                       6


     (3) To sell, transfer, relinquish, release, abandon or otherwise dispose of
any Joint Venture property or any interest therein or contractual right to
acquire the same from any Person;

     (4) To hold and administer Joint Venture property and to purchase and
maintain inventories of equipment, material, and machinery, and to hold, invest
and reinvest the assets of the Joint Venture;

     (5) To employ and retain any Person or Persons as agent, employee,
consultant or independent contractor of the Joint Venture, and to employ such
legal, accounting, and engineering services and other professional advice as the
Management Committee shall deem advisable;

     (6) To contract for third party services and equipment;

     (7) To engage in all such other activities related to the purposes of the
Joint Venture as are not prohibited by applicable law or the provisions of this
Agreement.

     2.5 Limitations. Unless the Parties otherwise agree in writing, operations
of the Joint Venture shall be limited to the purposes stated in Section 2.3 and
the powers stated in Section 2.4. Nothing in this Agreement shall be construed:

     (1) To authorize any Party to act as agent for another Party except as
provided in this Agreement; or

     (2) To permit any Party to undertake the conduct of any other business on
behalf of another Party; or

     (3) To enable the Joint Venture to incur any cost for implementing the
public interest strategy; or

     (4) To enable any Party to borrow money or incur obligations or behalf of
the Joint Venture, to use the credit of another Party or of the Joint Venture
for any purpose, or to pledge, assign or otherwise encumber the Assets except as
provided in this Agreement; or

     (5) To cause the Joint Venture to be responsible for the development of the
refueling station infrastructure except for refueling facilities on the Joint
Venture's premises; or

     (6) To enable the Joint Venture to provide financing of customer
conversions.

     2.6 Other Business Opportunities. Except as expressly provided in this
Agreement, each Party shall have the right to independently engage in and
receive full benefits from other business activities, whether or not competitive
with the operations of the Joint Venture, without consulting the other Parties.
During the term of this


                                       7


Agreement, NGVD shall not engage in, directly or indirectly, business activities
competitive with the business of the Joint Venture ("Competitive Activities") in
the Territory. Notwithstanding the foregoing, NGVD and its affiliates may
continue to sell CNG Cylinders and NGV Conversion Kits to the Joint Ventures'
competitors in the "Territory." As used herein, "Territory" means southern
California, including and south of the counties of San Luis Obispo and Fresno.

     2.7 Term. The term of this Agreement shall commence on the Effective Date
and shall continue until terminated by the occurrence of any one of the
conditions described in Section 14.1 and thereafter until all Assets have been
disposed of and a final accounting has been made between the Parties as provided
in Section 14.3.

     2.8 Tax Election, Tax Returns, and Allocations. The Parties recognize that
this Agreement creates a partnership for federal and state income tax purposes,
and the Parties do hereby agree not to elect to be excluded from the application
of Subchapter K of Chapter I of Subtitle A of the Internal Revenue Code or any
similar state statute. Federal, state and foreign partnership income tax returns
shall be timely filed by the Joint Venture with no more extensions than are
reasonably required. The Tax Matters Partner, in consultation with the Manager,
shall prepare and file the partnership tax returns and make appropriate
elections and allocations on such returns in accordance with the accounting
procedures described in Exhibit "C".

     2.9 Termination of Rights to Assets. Except as otherwise provided in this 
Agreement, no Party shall permit or cause all or any part of its interest in the
Assets or the Joint Venture to be sold, exchanged, encumbered, surrendered,
abandoned or otherwise terminated.

     2.10 Staff.

     (1) The Joint Venture's staff will include the Manager, a controller and
such mechanics, technicians, and support personnel as are necessary to carry out
the business purposes of the Joint Venture efficiently and profitably.

     (2) The Joint Venture intends not to discriminate on the basis of union
affiliation or the lack thereof.

     2.11 Office and Work Facilities.

     (1) The Joint Venture shall lease a facility (primary facility) in the Los
Angeles marketing area. The Los Angeles facility will be outfitted with a full
FTP emissions testing and systems analysis laboratory. All initial leasehold
improvements specific to the laboratory installation and the activities of the
Joint Venture shall be at the expense of the Joint Venture as described in the
approved budget. All initial leasehold improvements normally and regularly
provided by the property owner will be provided by the landlord, all of which
shall be identified in the lease.


                                       8


     (2) The early conversion work will be performed at the NGVD facility in
Long Beach or in facilities leased on a monthly basis until the Primary Facility
is ready for occupancy (estimated January 1, 1994).

     (3) The Joint Venture will make office space and support services available
to a University (to be selected by the Management Committee) for its oversight
activities.

     2.12 Development of Funding

     (1)  Customer Financing:

          The Joint Venture will not provide financing for any of its products
          and services;

     (2)  Lab Testing:

          The Joint Venture will pursue federal grants and other sources of
          outside funding to support the lab testing function.

     2.13 Market Area. The market area for the Joint Venture will be the
Territory as defined in Section 2.6.

     2.14 Expert Oversight Agency. The Joint Venture will seek to establish a
University (to be selected by the Management Committee) as an expert oversight
agency to monitor and document natural gas vehicle emissions and performance.

     2.15 Start-up Costs. Each Party shall absorb its own costs related to the
formation of the Joint Venture.

                                   ARTICLE III

                            CONTRIBUTIONS BY PARTIES

     3.1  Aggregate Equity Contributions by the Parties will be $2,070,000
Dollars. Total contributions to be paid by each of the Parties is as follows:

          NGVD:   One Million Thirty-Five Thousand Dollars ($1,035,000)
          ECA:    One Million Thirty-Five Thousand Dollars ($1,035,000)

     3.2 NGVD's Equity Contribution. At the time of its execution of this
Agreement NGVD shall deliver to the capital of the Joint Venture its One Million
Thirty-Five Thousand Dollars ($1,035,000) non-interest bearing capital
contribution promissory note (See Exhibit "D") which shall be secured by NGVD's
interest in the Joint Venture and which shall be payable in unequal payments as
shown on Exhibit "A". NGVD shall contribute as in kind, equity contributions,
its technical expertise in


                                       9


regard to underhood technology, cylinder application, conversion quality and
vehicle performance standards, management expertise in organizing and operating
this type of facility, goods and services and its existing laboratory upgraded
to perform gas speciation analysis.

     3.3 ECA's Equity Contribution. At the time of its execution of this
Agreement ECA shall deliver to the capital of the Joint Venture its One Million
Thirty-Five Thousand Dollars ($1,035,000) non-interest bearing capital
contribution promissory note (See Exhibit "D") which shall be secured by ECA's
interest in the Joint Venture and which shall be payable in unequal payments as
shown on Exhibit "A".

     3.4 Additional Contributions. After the Parties have made their Equity
Contributions, the Management Committee may, for approved Programs and Budgets
and subject to the consent of all of the Parties to this Agreement, call for
additional contributions from the Parties. In response to such call for
additional contributions, each Party shall contribute additional funds or
In-Kind Contributions in proportion to its Participating Interest. The
Management Committee may also reduce the amount of contributions required of
the parties.

     3.5 In-Kind Contributions. All or a portion of any Party's Equity
Contributions, including NGVD's In-Kind Contributions described in Section 3.2
(above) and any other capital contributions, may be comprised of in-kind
contributions ("In-Kind Contributions") of laboratory equipment for use by the
Joint Venture, CNG cylinders and underhood kit materials to stock the Joint
Venture's inventory and other real or personal property. All such In-Kind
Contributions that are additional to those described on Attachment "D" must be
approved in advance by the Management Committee. All In-Kind Contributions shall
be free and clear of any liens or encumbrances. For In-Kind Contribution
credits: (i) the personal property and real property shall be valued at, subject
to independent appraisal, its fair market value, considering age and condition;
and (ii) CNG Cylinders shall be valued in accordance with the terms and
conditions of Section 6.3. A prototype of an NGVD Master Distributor Price Sheet
is attached to this Joint Venture Agreement as Exhibit "B".

     3.6 Late Payments. Any party that fails to make equity contributions will
be subject to the default provisions (Article XII).

                                   ARTICLE VI

                      INTERESTS AND UNDERTAKINGS OF PARTIES

     4.1 Participating Interests.


                                       10


     (1) The two Parties shall have equal Participating Interests in the
profits, losses, assets and notes of the Joint Venture:

                     NGVD:    Fifty Percent (50%)
                     ECA:     Fifty Percent (50%)

     4.2 NGVD Undertakings. In addition to its other obligations and
responsibilities enumerated in this Agreement, including Exhibit "D" NGVD agrees
to:

     (1) Provide specialized technical assistance, as approved in advance by the
Management Committee.

     (2) Provide training for conversion workers.

     (3) Support the Joint Venture's marketing activities.

     (4) Assist with the development and maintenance of a system of Internal
Controls which shall be implemented by NGVD and approved by the Management
Committee to provide reasonable assurance that:

          (a)  The Joint Venture's assets are safeguarded against loss or
               unauthorized use; and

          (b)  The Joint Venture's financial records are adequate and reliable
               for preparation of financial statements and other financial
               data.

     4.3 ECA Undertakings. In addition to its other obligations and
responsibilities enumerated in this Agreement, ECA agrees to:

     (1) Act as the Tax Matters Partner;

     (2) Assist with the development and maintenance of a system of internal
controls which shall be implemented by NGVD and approved by the Management
Committee to provide reasonable assurance that:

          (a)  The Joint Venture's assets are safeguarded against loss or
               unauthorized use; and

          (b)  The Joint Venture's financial records are adequate and reliable
               for preparation of financial statements and other financial data.

     (3) Provide access to the NGV marketing information that is available to
the general public at ECA. 


                                       11


     (4) Provide oversight for the Joint Venture's real estate activities.

                                    ARTICLE V

                              Management Committee

     5.1 Organization and Composition. The Parties shall conduct the business of
the Joint Venture through a Management Committee, which shall determine overall
policies, objectives, procedures, methods and actions under this Agreement. NGVD
and ECA shall each appoint two members to the Management Committee. Each Party
may appoint one or more alternates to act in the absence of a regular member.
Any alternate so acting shall be deemed to be a member. Appointments shall be
made or changed by written notice to the other Parties. Each committee member
may bring such technical and other advisors as it deems appropriate to all
Management Committee meetings.

     5.2 Chairmanship. One of NGVD's members of the Management Committee will be
designated as chairman of the Management Committee for the balance of 1993.
Thereafter, the chairmanship will be alternated between the members designated
by each Party, beginning with ECA's member in 1994.

         1994 - ECA's member

         1995 - NGVD's member

         1996 - ECA's member

     5.3 Decisions. Each Party shall vote and act through its appointed members
on the Management Committee, unless otherwise provided in this Agreement.
Decisions made by the Management Committee shall be by the unanimous consent of
all members of the Management Committee. In the event of an impasse having a
materially adverse effect on Joint Venture operations, the matter shall be
determined by binding arbitration in accordance with Section 12.4; provided,
however, that, without its express written consent, no Party shall be required,
through arbitration or otherwise, to make any additional contributions, advances
or loans to, or to pay or guarantee any obligations or indebtedness of, the
Joint Venture except as expressly provided in this Agreement.

     5.4 Meetings. The Management Committee shall hold regular meetings at least
quarterly at any mutually agreed place. Unless otherwise agreed, the quarterly
meetings shall be held at 10:00 a.m. on the first Friday in March, June,
September and December in Los Angeles, California. The Manager shall give the
Parties thirty (30) days notice of regular meetings, but receipt by all Parties
of such thirty (30) day notice shall not be a prerequisite for the holding of a
regular meeting. Any Party may call a special meeting upon ten (10) days notice
to the other Party. In case of emergency, reasonable notice of a special meeting
shall suffice.


                                       12


     Notice may be waived by the written consent of the Management Committee
members. A quorum for any meeting shall consist of one member representing each
Party. However, if any Party fails to attend two consecutive properly called
meetings, then a quorum shall consist of the members representing the other
Party and such Parties' vote shall be considered a unanimous vote for the
purposes of the conduct of all business properly noticed.

     Each meeting notice shall include an itemized agenda prepared by the
Manager and including all matters proposed for the consideration by any Party in
the case of a regular meeting, or by the Party calling the meeting in the case
of a special meeting, nut any matters may be considered if any Party adds the
matter to the agenda by notice to the other Parties at least 48 hours before the
meeting. Each notice shall include a copy of any document as to which action is
to be taken. Supplemental information may be requested by any Party.

     The Manager shall prepare minutes of each meeting and shall distribute
copies of the minutes to the Parties within three (3) days after the meeting.
Each Party shall return to the Manager signed minutes or specific objections
within thirty (30) days of receipt. If an objection to the minutes is received
and not resolved by the Parties at least three (3) days prior to the next
meeting of the Management Committee, the minutes in dispute shall again be
considered at the next meeting of the Management Committee when final minutes
shall be agreed upon. The minutes, when signed by all Parties, shall be the
official record of the decisions made by the Management Committee and shall be
binding on the Parties.

     The Manager shall attend all Management Committee meetings unless the
Management Committee requests that he not be in attendance at a specific
Management Committee meeting. By specific request of the Management Committee,
other personnel employed in Joint Venture operations also may be required to
attend a Management Committee meeting. Reasonable costs incurred in connection
with such Management Committee meeting attendance by the Manager and other
Joint Venture personnel shall be Joint Venture costs.

     5.5 Action Without Meeting. In lieu of meetings, the Management Committee
may hold telephone conferences, so long as minutes of such meetings are promptly
distributed to the Parties and shall become effective when signed by the members
of the Management Committee and returned to the Chairman. The Management
Committee, in lieu of deciding any matter at a meeting or by telephone
conference, may act by instrument in writing signed by each member of the
Management Committee.

     5.6 Matters Requiring Management Committee Approval. The Management
Committee shall have exclusive authority to make all major policy, financial and
operating decisions associated with the Joint Venture and with this Agreement,
including but not limited to

     (1) Requiring additional capital contributions from the Parties in
accordance with Section 3.4 of this Agreement;


                                       13


     (2) Approving Joint Venture Financing

     (3) Approving plans or standards for distribution of Joint Venture cash;

     (4) Approving acquisition or disposition of Assets of the Joint Venture,
which exceeds Five Thousand Dollars ($5,000) in value or is not in the budget;

     (5) Approving the assumption, guarantee or approval of the incurrence of
any obligation for borrowed money, or the approval of other Joint Venture
Financing arrangements on behalf of or in the name of the Joint Venture
including any obligation for borrowed money secured by any encumbrance in
respect of the Joint Venture, even though the Joint Venture has not assumed or
become liable for the payment of such obligation;

     (6) Approving making any investment not in the ordinary course of business,
whether by stock purchase, capital contribution, loan or advance or by purchase
of property or otherwise, on behalf of or in the name of the Joint Venture;

     (7) Approving the sales of any notes or accounts receivable of the Joint
Venture with recourse, at a discount or otherwise, for less than the fair market
value thereof. Notwithstanding this provision, the Manager shall have the
ability, within guidelines to be established by the Management Committee, to
give volume discounts and other price allowances on the sale of goods or
services by the Joint Venture;

     (8) Retaining any law firm or accounting firm to represent the Joint
Venture;

     (9) Determining actual sales and marketing programs for the Joint Venture;

     (10) Selection of General Manager and Controller; and

     (11) Approving Transfer of Management or Key Personnel.

                                   ARTICLE VI

                                     MANAGER

     6.1 Appointment. The Management Committee shall appoint a manager with
overall responsibility for all Operations from the Effective Date. The Manager
shall serve in such capacity until he resigns or is replaced. The Parties direct
the Manager to perform the duties of the Manager of the Joint Venture subject to
the terms and conditions of this Agreement. The Parties agree that at all times
the Manager shall be the agent of the Joint Venture for conducting Operations
on behalf of the Joint Venture and for the performance of such other duties as
are imposed on the Manager by the Parties under or pursuant to the provisions of
this Agreement. The Manager shall consult freely with the Management Committee.
The Manager shall receive compensation for the performance of his duties in an
amount to be determined by the Management Committee.


                                       14


     6.2 Powers and Duties of Manager. Subject to the terms and provisions of
this Agreement, approved Programs and Budgets, and the supervision and direction
of the Management Committee, the Manager shall have the powers and duties to:

     (1) Manage, direct and control all Operations in accordance with approved
Programs and Budgets and in accordance with the other provisions of this
Agreement;

     (2) Take all actions, perform all duties and make or incur such
expenditures as are required to maintain the titles and interests of the Joint
Venture in and to the Assets;

     (3) Arrange for and carry out Operations, including but not limited to
obtaining such competent consultants, technicians, agents, employees and
independent contractors as may be required and purchasing and selling such
materials, supplies, equipment and services as may be required in connection
with Operations and entering into such contracts exclusively on behalf of the
Joint Venture as may be necessary in connection therewith in accordance with
contracting guidelines approved by the Management Committee. Such contracting
guidelines shall, among other things, specify that such contracts shall not be
for a term greater than 12 months, nor for a quantity in excess of that which
the Joint Venture is reasonably expected to consume in such period; (ii) that
the vendor/contractor protect, indemnify and/or insure the Joint Venture against
(a) personal injury and property damage arising from defects in materials and
labor supplied and (b) claims of infringement and unlawful use of patents,
know-how and proprietary rights, and (iii) that the terms of such contracts
otherwise be at least as favorable to the Joint Venture as those usual and
customary in the industry. As to Operations conducted pursuant to an approved
Program and Budget, the Manager may not exceed five percent (5%) of any budgeted
line item and shall not exceed the Budget by more than Five Thousand Dollars
($5,000) in the aggregate without the prior approval of the Management
Committee. Fixed assets may be sold by the Manager without Management Committee
approval only if the sale meets all of the following criteria:

     (a)  It is no longer required for Operations; and

     (b)  It has fair market value of Five Thousand Dollars ($5,000) or less;
          and

     (c)  The fair market value equals or exceeds the net book value of the
          equipment.

All fixed asset sales and purchases over Five Thousand Dollars ($5,000) must be
specifically approved by the Management Committee as part of a Program and
Budget;

     (4) Protect the interest of the Parties in connection with the valuation of
the Assets by public authorities for tax purposes;


                                       15


     (5) Conduct Operations in compliance with all applicable statutes,
regulations and orders of federal, state and local governmental bodies,
including but not limited to those relating to safety requirements, working
conditions, equal opportunity and affirmative action, workers' compensation,
employee benefits, and environmental protection, and secure all licenses,
permits and approvals necessary for Operations;

     (6) Supervise the keeping of full and accurate records and accounts of all
transactions' entered into on behalf of the Parties and of all Joint Venture
costs and of all funds disbursed by it or under its direction in accordance with
the Joint Venture's accounting procedures;

     (7) Supervise the preparation and distribution of reports of each Party on
Operations and Finances in accordance with Article VIII;

     (8) Prepare and maintain minutes of all Management Committee meetings and
related correspondence;

     (9) In case of emergency, take any action the Manager deems necessary to
protect life, limb or property, to protect the Assets or to comply with law or
government regulation;

     (10) Notify the Management Committee of any material event or action
affecting Operations as soon as possible following such event or action;

     (11) Undertake compliance with all relevant State and Federal withholding
tax and unemployment tax requirements with respect to Joint Venture employees;
and

     (12) Have such additional powers and duties as the Management Committee may
direct.

     6.3 Transactions with Parties or their Affiliates. If the Manager engages
Affiliates of the Parties to provide products and services to be used in the
conduct of the Joint Venture business, be shall do so on terms no less
favorable to the Joint Venture than would be the case with unrelated persons in
arm's-length transactions and shall do so only with the approval of the
Management Committee. The purchase price for CNG Cylinders purchased from CNG
Cylinder Company shall be the lesser of: (a) Eighty-Six percent (86%) of the
price shown on the then effective Price Sheet of its Master Distributor Pricing;
or (b) the lowest price (net of freight costs) then being charged for similar
quantities to any other NGVD customer in the United States. The Joint Venture's
purchase price for NGV Conversion Kits shall be no more than the lowest price
(net of freight costs) then being charged for similar quantities to any other
NGVD customer in the United States.

     6.4 Standard of Care and Liability. The Manager shall conduct and manage
the Operations and perform all of his obligations as Manager in a workmanlike
and commercially reasonable manner, using his prudent business judgment for the
benefit of the Joint Venture.


                                       16


                                   ARTICLE VII

                              PROGRAMS AND BUDGETS

     7.1 Operations Pursuant to Programs and Budgets. Operations shall be
conducted, expenses shall be incurred, and Assets shall be acquired only
pursuant to Programs and Budgets approved by the Management Committee.

     7.2 Content of Programs and Budgets. Each annual Program and Budget shall
describe in reasonable detail the full nature and extent of the proposed
operations. The Budget for each year shall also include, as applicable, all
anticipated costs and expenses, including but not limited to development,
operation and maintenance expenditures, capital expenditures, working capital
requirements, and a statement of all anticipated cash calls for the ordinary,
necessary operating costs of the Joint Venture, as well as extraordinary capital
or acquisition expenses. Each Budget shall also include quarterly production and
marketing schedules and forecasts, as applicable, with costs estimates and
budgets in sufficient detail to conform with industry standards.

     7.3 Presentation of Programs and Budgets. Proposed Programs and Budgets
shall be prepared by the Manager and, after the initial Program and Budget,
shall be for one Contract Year. Each adopted Program and Budget, regardless of
how many years it covers, shall be reviewed at least once a year at the December
regular meeting of the Management Committee.

     7.4 Program and Budget for Initial Period. The Program and Budget for the
period from the Effective Date through December 31, 1993 and the 1994 program
are attached as Exhibit "A", and are hereby adopted.

     7.5 Review and Approval of Proposed Program and Budget.

     7.5.1 Presentations. The Manager will present the proposed Program and
Budget to each member of the Management Committee of this Joint Venture no later
than thirty (30) days before the date of the December quarterly Management
Committee meeting. Within ten (10) days after receipt of the Manager's proposed
Program and Budget, a Party may propose modifications to the Manager's proposal
or alternatives to the proposed Program and Budget. At the meeting, the
Management Committee will consider the proposed Program and Budget and any
suggested modifications or alternatives and will vote to approve or reject a
Program and Budget.

     7.5.2 Deadlock. If the Management Committee for any reason fails to approve
a Program and Budget within the time provided in Section 7.5.1 for any Contract
Year, then no cash of the Joint Venture may be distributed to the Parties from
the date of such deadlocked December quarterly meeting until a Program and
Budget for such Contract Year is approved.


                                       17


     7.5.3 Modifications. The Management Committee will monitor the Joint
Venture's actual results versus the approved Program and Budget regularly and
will make modifications to the Program and Budget as necessary.

                                  ARTICLE VIII

                            ACCOUNTS AND SETTLEMENTS

     8.1 Monthly Cash Budget. The Manager shall promptly submit to the Parties
monthly statements of account reflecting in reasonable detail the charges and
credits to the Joint Venture. The monthly statement shall show:

     (1) The estimated amount that will be required to be raised during the
succeeding calendar month (or such longer period as may be determined by the
Management Committee) for the approved Program and Budget;

     (2) The portion of any Joint Venture Financing debt which is due and
payable in the succeeding calendar month;

     (3) The extent, if any, to which the above amounts may be satisfied by
funds (in excess of a proper amount of Joint Venture working capital) previously
furnished to the Joint Venture under this Agreement or Gross Proceeds on hand;

     (4) Credits to the Joint Venture, if any, including those arising from
adjustment of accruals to the actual expenditures; and

     (5) A summary of the Joint Venture's activities and the results of such
activities.

     (6) Such other information as the Management Committee may direct.

     The monthly cash budget shall include an amount to cover the monthly
general expenses of the Joint Venture, an amount to cover the anticipated
expenditures during the succeeding month for approved Operations and an amount
required to maintain reasonable working capital.

     8.2 Accounts. The Manager shall maintain at the Joint Venture's principal
office complete financial books and records, on the accrual basis for financial
reporting in accordance with generally accepted accounting principles, showing
all costs, expenditures, sales, receipts, disbursements, assets and liabilities,
and profits and losses. These accounts shall include general ledgers and
supporting and subsidiary journals, invoices, checks and other customary
documentation. The Manager shall also maintain at such offices all other records
necessary, convenient or incidental to the recording of the Joint Venture's
affairs. The accounts shall be retained for the duration of the period allowed
the Parties for audit or the period required by the Internal Revenue Code or the
needs of any Party.


                                       18


     8.3 Audits

     8.3.1 Independent Audits. The Joint Venture's financial statements shall be
audited annually by an independent certified public accounting firm selected by
the Management Committee. Such audit will take place annually and will be
completed within three (3) months after the end of each Contract Year. The cost
of such audit shall be borne by the Joint Venture. The Parties and any
Authorized Person shall have the right at any time to meet and discuss affairs,
finances and accounts of the Joint Venture with the independent public
accountants conducting any such audit. The Manager shall promptly deliver the
Management Committee a copy of any report as to the material inadequacies in
accounting controls, or the absence thereof, submitted by the independent public
accountants in connection with any audit of the Joint Venture.

     8.3.2 Party's Audits. Any Party and any Authorized Person may, upon
reasonable notice, at its sole expense and at reasonable times, inspect, examine
and audit the accounts and records of Operations under this Agreement. Upon the
request of a Party, the Manager shall provide a detailed accounting reconciling
beginning and ending balances in any of the Joint Venture accounts.

     8.3.3 Resolution of Audit Disputes. Any disputes arising out of audits
shall be addressed promptly by the Management Committee at a meeting called for
such purpose. If the Management Committee fails to resolve such dispute to the
satisfaction of all Parties, then the Parties shall be left with all their
remedies at law and equity and all of their remedies under this Agreement. All
written exceptions to the independent audit shall be made within the 12-month
period after the auditor's report for the period under examination is made
available to the Parties.

     8.4 Annual Reports and Records. Within ninety (90) days after the end of
each Contract Year, the Manager shall furnish to each of the Parties: (a) a
detailed report on the activities of the Joint Venture during that Contract
Year, reporting the results of all Operations; and (b) an annual Joint Venture
financial statement, which shall include statements of income, cash flow and
balance sheets prepared in conformity with generally accepted accounting
principles (consistently applied) for the Contract Year then ended and any
additional information that the Parties may reasonably require.

     8.5 Monthly Report. On or before the 20th day of each month, the Manager
shall prepare and submit to the Parties a monthly report showing the actual
results of Operations for the preceding month in sufficient detail for
computation and monitoring of all phases of Operations. The report shall also
include other information Consistent with generally accepted accounting
principles (consistently applied) and cost accounting procedures consistent with
standards in the industry. The monthly report shall include information
comparing actual Joint Venture expenditures to budgeted expenditures,
anticipated Operations over the next six months with notations of any material
events, and explanations of any significant differences between actual results
and those budgeted or previously forecast. The Management Committee shall review
such reports on at least a quarterly basis.


                                       19


     8.6 Inspection and Access. The Parties or any Authorized Person shall be
permitted, at any and all reasonable times, to inspect and copy the Manager's
books, records and data pertaining to the Joint Venture.

     8.7 Additional Information. Each Party or its Authorized Person shall have
the right to discuss the affairs, finances and accounts of the Joint Venture
with the officers and employees of the Joint Venture. The Manager shall, in
addition to the foregoing, make available to the Parties and their Authorized
Persons such other information relating to the affairs of the Joint Venture as
the Party or any Authorized Person may from time to time reasonably request.

                                   ARTICLE IX

                 DISTRIBUTION AND ALLOCATION OF INCOME AND LOSS

     9.1 Distribution of Partnership Cash or Property. Excess Partnership Cash.
After providing for the payment of any amounts due on the indebtedness of the
Joint Venture, current operating costs, working capital, reserves for
contingencies and other obligations, and subject to Section 7.5.2 and other
limitations of this Agreement, the Management Committee will twice per year at
reasonable intervals (or at such other times as the Management Committee shall
unanimously agree to) distribute any remaining cash or property in kind of the
Joint Venture to the Parties in proportion to their Participating Interests
(provided however, that in the event of dissolution, all distributions shall be
made pursuant to Section 14.3 hereof).

     9.2 Net Income and Net Gain. The net income and net gains of the Joint
Venture for each fiscal year of the Joint Venture shall be allocated to the
Parties in proportion to their Participating Interests.

     9.3 Net Loss. Net loss of the Joint Venture for each fiscal year of the
Joint Venture shall be allocated to the Parties in proportion to their
Participating Interests.

     9.4 Joint Loss of Title. Any failure or loss of title to the Assets shall
be charged to the Joint Venture and allocated among the Parties in proportion to
their Participating Interests, provided however that, with respect to assets
contributed to the Joint Venture in-kind by a Party, such failure or loss shall
be borne solely by the contributing Party and such Party shall indemnify and
hold harmless the Joint Venture and the other Parties with respect to such
failure or loss. All costs of defending title shall be charged to the Joint
Venture or to the Party contributing such assets, as the case may be.

     9.5 Liability or Loss in Excess of Insurance. Any liability, loss, damage,
claim, or expense resulting from occurrences not covered by or in excess of
insurance carried for the Joint Venture shall be borne by the parties hereto in
accordance with Article XIII.


                                       20


                                    ARTICLE X

                                    INSURANCE

     10.1 Prior to the Joint Venture's commencing business, a comprehensive
property and casualty insurance program for the Joint Venture shall be developed
by NGVD and ECA and submitted to the Management Committee for approval. The
insurance program shall include the following coverages which shall be
maintained with insurers approved by the Management Committee in amounts
determined by the Management Committee:

     (1) Workers' compensation insurance as may be required under the laws of
any relevant jurisdiction;

     (2) Employer's Liability Insurance;

     (3) Comprehensive general liability insurance covering the contractual
liability of the Joint Venture. This policy shall also cover liability of the
Joint Venture related to bodily injury, death or property damage occurring:

     (a)  in or about any premises owned or occupied by the Joint Venture; or

     (b)  as a result of the use of products manufactured, constructed or sold
          by the Joint Venture; or

     (c)  as a result of the services rendered by and the completed operations
          of the Joint Venture.

     (4) Automobile liability insurance for bodily injury, death or property
damage arising as a result of the ownership, maintenance or operation by the
Joint Venture of any automobile, truck or other motor vehicle or related to
uninsured motorists; and

     (5) Such other insurance coverage as is required by the Management
Committee.

     10.2 With the exception of Workers' Compensation, Employers Liability, and
General Partnership Liability insurance, each Party and its owner, directors,
officers, Management Committee Members, and employees shall be additional
insureds on all of the Joint Venture's policies with respect to claims or
liabilities arising out of actions or omissions in conducting Joint Venture
activities. However, any person or entity providing products which are used by
the Joint Venture in the conversion of vehicles to natural gas power including
Affiliates (other than the Joint Venture) of such persons or entities, shall not
be covered under any of the Joint Venture's insurance policies for claims
arising therefrom. NGVD and ECA shall require the appropriate representative or
agent of the insurance company affording coverage to provide each


                                       21


party with a certificate of insurance for each coverage which states the
effective dates and expiration dates of the policies and provides that the
policy will not be changed or canceled until thirty (30) days written notice has
been given to each party. NGVD and ECA shall insure that each party obtains a
true, correct and complete copy of the insurance policies as soon as
practicable.

     10.3 NGVD and ECA shall be responsible for maintaining the approved
insurance program in full force and effect for the benefit and at the expense of
the Joint Venture. Invoices for insurance payments shall be certified by the
Management Committee for payment by the Manager.

                                   ARTICLE XI

                         REPRESENTATIONS AND WARRANTIES

     11.1 Capacity of Parties. Each of the Parties represents and warrants as
follows:

     (1) That it is a legal entity duly organized and in good standing in itS
state of organization and that it is, or will promptly take all actions
necessary to become, qualified to do business in the State of California;

     (2) That it has the capacity to enter into and perform this Agreement and
all transactions contemplated herein and that all corporate or other actions
required to authorize it to enter into and perform this Agreement have been
properly taken;

     (3) That it will not breach any other agreement or arrangement by entering
into or performing this Agreement and that this Agreement has been duly executed
and delivered by it and is valid and binding upon it in accordance with its
terms;

     (4) That it has fully compensated or will fully compensate any broker or
finder that has acted on its behalf in connection with the negotiation,
execution or delivery of this Agreement; and

     (5) That it has not made any assignment for the benefit of creditors, filed
any petition in bankruptcy, been adjudicated insolvent or bankrupt, petitioned
or applied to any tribunal for any receiver, conservator or trustee of it under
any reorganization arrangement, readjustment of debt, conservation, dissolution
or liquidation law or statute of any jurisdiction, and no such action or
proceeding has been commenced against it by any creditor, claimant, governmental
agency or other person.

     11.2 Compliance with other Agreements. Each Party agrees that it will
comply with all of the terms, conditions and provisions on its part to be
observed or performed under any lease, agreement or other instrument pursuant to
which Assets have been acquired provided, however: (1) that breaches and
defaults that are timely cured under any such lease, agreement or instrument,
and failures to comply with the terms of any such lease, agreement or instrument
that do not jeopardize the title to 


                                       22


Assets, Operations or other material interests of the Joint Venture shall not be
considered events of default under Article XII, and (2) that the Party will not
terminate or cancel any such lease, agreement or other instrument and will take
all actions requisite on its part to prevent any termination or cancellation
thereof, other than termination by the consent of the Parties or Termination for
reasons beyond the control of both Parties. Each Party agrees to notify the
other Party promptly in writing if it receives notice of any default or alleged
default under any such lease, agreement or instrument, or notice of any title
defect or alleged title defect affecting the Assets.

                                   ARTICLE XII

             PARTIES' DEFAULTS AND REMEDIES: ARBITRATION OF DISPUTES

     12.1 Events of Default. The following events shall constitute events of
default:

     (1) Any transfer by a Party of its interest in the Joint Venture in
contravention of the provisions of Article XV;

     (2) Failure of a Party to make any portion of an Equity Contribution when
due;

     (3) Failure of a Party to perform any other obligation imposed upon such
Party by this Agreement;

     (4) Filing of a petition in bankruptcy by or against a Party if such
petition is not withdrawn or dismissed within sixty (60) days after its filing;

     (5) Assignment by a Party for the benefit of creditors; or

     (6) Allowance by a Party of the appointment of a receiver or trustee for
all or any part of its property if such receiver or trustee is not discharged
within sixty (60) days after his appointment.

     Upon the occurrence of any such event, the Party failing to perform shall
be deemed to be in default hereunder and shall be referred to as the "Defaulting
Party", and any other Party shall be referred to as a "Non-Defaulting Party".

     12.2 Notice of Default. Any Non-Defaulting Party shall have the right to
give the Defaulting Party a Notice of Default, which shall be in writing, shall
set forth the nature of the event of default, and shall set forth the date by
which such default must be cured, which date shall be at least thirty (30) days
after receipt of the Notice of Default, except as to subsections (1), (4), (5)
and (6) of Section 12.1, as to which there will be no cure period. Failure of
any Non-Defaulting Party to give any such notice shall not release the
Defaulting Party from any of its obligations under this Agreement.


                                       23


     12.3 Opportunity to Cure. If within such thirty (30) day cure period,
except with respect to events of default under Subsection (2) of Section 12.1,
the Defaulting Party cures such default, or if the failure is one that cannot in
good faith be corrected within thirty (30) days and the Defaulting Party begins
correction of such failure to perform within such thirty (30) days and continues
corrective efforts with reasonable diligence until a cure is effected, the
Notice of Default shall be inoperative, and the Defaulting Party shall lose no
rights hereunder. If, within such specified periods, the Defaulting Party does
not cure or commence to cure such default as provided above, or if within such
thirty (30) day period the Defaulting Party notifies the Non-Defaulting Parties
that it disputes the existence of the alleged default and the Defaulting Party
shall not have commenced correction of the default within thirty (30) days after
the entry of an arbitrator's decision under Section 12.4 confirming the
existence of the alleged default, the Non-Defaulting Parties at the expiration
of such period, or upon notice where no cure period is allowed, shall have the
rights specified in Section 12.5.

     12.4 Arbitration of Disputes. Disputes between or among the Parties arising
out of or relating to this Agreement (other than routine management decisions)
shall be resolved through binding arbitration according to the commercial rules
of the American Arbitration Association ("Association"), except to the extent
that such rules are inconsistent with the terms of this Section. Unless
otherwise agreed by the Parties, such arbitration shall not be conducted under
the auspices of the Association. All arbitrations shall occur in Los Angeles,
California. Notwithstanding this agreement to arbitrate all disputes, each Party
shall be entitled to petition in a court of law for any relief necessary to
prevent irreparable harm to such Party prior to the entry of the arbitrators'
decision and each Party shall have the right to discovery conducted in
accordance with the Federal Rules of Civil Procedure, except that the
arbitrators shall have and exercise the powers allocated to the court by such
Rules. The arbitration committee will consist of three arbitrators. One
arbitrator will be appointed by each Party to a given dispute with the third
arbitrator to be selected by the two arbitrators designated by the disputing
Parties. An arbitration hearing will commence within thirty (30) days after
appointment of the arbitration committee. Unless the arbitrators find that
exceptional circumstances justify delay, the hearing will be completed, and an
award will be rendered in writing, within forty (40) days after commencement of
the hearing. If the arbitrators determine that a dispute is frivolous, they may
assess the Joint Venture's and the "winning" Party's costs resulting from the
arbitration proceeding to the losing party. In the event of manifest injustice
the arbitrators award shall be subject to judicial review, with respect to
issues of law only. The Parties hereby waive trial by jury in any proceedings
arising out of or relating to this Agreement.

     12.5 Rights upon Default. After providing notice and an opportunity to cure
as provided in Sections 12.2 and 12.3 above, and, in the event of a dispute with
respect to the alleged default, after the entry of an Arbitrators' decision
confirming the default, the Non-Defaulting Party shall be entitled (but not
required) to exercise any power or remedy now or hereafter exercisable at law or
in equity (including the right to specific performance), and each and every
power and remedy may be exercised


                                       24


from Time to time and as often and in such order as may be deemed expedient. All
such powers and remedies shall be cumulative, and the exercise of one shall not
be deemed a waiver of the right to exercise any other or others. No delay or
omission in the exercise of any such power or remedy shall impair any such power
or remedy or shall be construed to be a waiver of any default or an acquiescence
therein. The Defaulting Party shall cease to have the right to participate in
the management of the Joint Venture beginning immediately after the period for
cure expires and continuing for so long as the default continues, and the
Defaulting Party during such period shall have no vote in Management Committee
decisions. In continuing to manage the Joint Venture, the Non-Defaulting Party
shall have absolute discretion and may remove and replace the Manager and manage
the Operations in conformity with Article VI above. No action taken by the
Non-Defaulting Party shall subject it to claims for breach of duty, on the
ground of conflict of interest, negligence or any other theory, except fraud or
gross negligence. In no event shall any Party be liable for loss of profits, nor
for any punitive, incidental or consequential damages arising from any action or
inaction relating to this Agreement, except as required under Article XII,
Indemnity.

     12.6 Non-Recourse Obligations. All obligations of NGVD hereunder shall be
the sole responsibility of NGVD and, in the absence of an express written
assumption thereof, neither ECA nor any party on its behalf shall have any
recourse to any other party (including, but not limited to NGVD's shareholders,
officers, directors or employees or NGVD's affiliates) for any breach by or
liability of NGVD arising Out of this Agreement; and likewise, all obligations
of ECA under this Agreement shall be the sole responsibility of ECA and, in the
absence of any express written assumption thereof, neither NGVD nor any party on
its behalf shall have any recourse against any other party (including, but not
limited to officers, directors, employees, shareholders or ECA's affiliates) for
any breach or liability of ECA arising out of this Agreement. The parties agree
that Southern California Gas Company shall have no obligations or liabilities
whatsoever under, or arising out of this Agreement.

                                  ARTICLE XIII

                                 INDEMNIFICATION

     Each Party agrees to indemnify, defend and hold harmless the other Party
and its directors, officers, employees and agents and, to the extent set forth
below, each Affiliate of the other Party, from and against all claims, causes of
action, liabilities, payments, obligations expenses (including without
limitation reasonable fees and disbursements of counsel) or losses arising out
of a Joint Venture liability or obligation, to the extent necessary to
accomplish the result that no Party or its Affiliates shall bear any portion of
a liability or obligation of the Joint Venture in any manner other than in
accordance with its Participating Interest at the time the liability accrues.
Without limiting the generality of the foregoing, a claim, loss or liability
shall be deemed to arise out of a Joint Venture liability or obligation if it
arises Out of, or is based upon, the conduct of the business of the Joint
Venture or the ownership or operation of the Joint Venture Assets. The foregoing
indemnification shall be available to an Affiliate of a Party with respect to a
claim, liability or loss arising out


                                       25


of a Joint Venture liability or obligation that is paid by or incurred by such
Affiliate solely as a result of such Affiliate directly or indirectly owning or
controlling a Party. The foregoing indemnity shall apply only to a claim,
liability or loss to the. extent that it is uninsured by the Joint Venture and
shall survive the dissolution or other termination of the Joint Venture. The
foregoing provisions shall not inure to the benefit of any Party or Affiliate in
respect of any claim, liability or loss that (1) is a tax, levy or similar law
or governmental charge not imposed upon the Joint Venture or upon its Assets;
(2) arises out of, or is based upon, the gross negligence, willful
misconduct, breach of warranty, or unauthorized binding of the Joint Venture to
an obligation by such Party grits Affiliate; or (3) arises out of the provision
of products by a Party or its Affiliate which are used by the Joint Venture in
the conversion of vehicles to natural gas power. In each such case, such Party
or Affiliate shall indemnify, defend and hold harmless ether Party and its
directors, officers, employees and agents from and against any and all claims,
causes of action, liabilities, payments, obligations, expenses (including
reasonable attorneys' fees and disbursements of counsel) or losses arising out
of such Party or its Affiliate's: (1) gross negligence, willful misconduct,
breach of warranty, or unauthorized binding of the Joint Venture to an
obligation; or (2) provision of products which are used by the Joint Venture in
the conversion of vehicles to natural gas power.

                                   ARTICLE XIV

                                   TERMINATION

     14.1 Termination. This Agreement is subject to termination as follows:

     14.1.1 Termination by Agreement. The Parties may terminate this Joint
Venture at any time by written agreement.

     14.1.2 Termination by Expiration. The Joint Venture shall terminate four
(4) years after Effective Date, and shall continue from year to year thereafter,
unless terminated on or after the fourth anniversary of the Effective Date by a
Party upon sixty (60 days prior written notice).

     14.1.3 Termination by Bankruptcy. The Joint Venture shall terminate upon
the filing of a petition in bankruptcy by or against a Party if such petition
is now withdrawn or dismissed within sixty (60 days after its filing.

     14.2 Continuing Obligations. On termination of this Agreement, the Parties
shall remain liable for continuing obligations hereunder until final settlement
of all accounts and for any liability, whether it arises before or after
termination, if it arises out of Operations during the term of the Agreement.

     14.3 Disposition of Assets on Termination. Promptly after termination, the
Manager shall take all action necessary to wind up the activities of the Joint
Venture, and all costs and expenses incurred in connection with the winding up
of the Joint


                                       26


Venture shall be expenses chargeable to the Joint Venture. Exhibit "C" shall
control the distribution and application to the Parties of the net proceeds of
liquidation of the Joint Venture Assets or, if applicable, the Joint Venture
Assets themselves upon termination.

     14.4 Right to Data After Termination. After termination of this Agreement
pursuant to Section 4.1 each Party shall be entitled to copies of all
information acquired hereunder as of the date of termination and not previously
furnished to it.

     14.5 Continuing Authority. On termination of this Agreement, the Manager
shall have the power and authority, subject to control of the Management
Committee, to do all things on behalf of the Parties that are reasonable,
necessary, or convenient to: (1) wind up Operations and (2) complete any
transaction and satisfy any obligation unfinished or unsatisfied at the time of
such termination, if the transaction or obligation arises out of Operations
prior to such termination. The Manager shall have the power and authority to
grant or receive extensions of time or change the method of payment of an
already existing liability or obligation, prosecute and defend actions on behalf
of the Parties and the Joint Venture, mortgage assets, and take any other
reasonable action in any manner with respect to which the former Parties
continue to have, or appear or are alleged to have, a common interest or a
common liability.

                                   ARTICLE XV

                              TRANSFER OF INTEREST

     15.1 General. A Party shall have the right, subject to the preemptive right
under Section 15.3 and the limitations below, to transfer, grant, assign,
encumber, pledge or otherwise commit or dispose of ("Transfer") to any third
party all or part of its interest in or to this Agreement upon the written
consent of the other Party, which consent may not unreasonably be withheld.

     15.2 Limitations on Free Transferability. The Transfer right of a Party in
Section 15.1 shall be subject to the following terms and conditions:

     (1) No transferee of all of the interest of a Party to this Agreement shall
have the rights of a Party, unless and until the transferring Party has provided
to the other Parties notice of the Transfer, and the transferee, as of the
effective date of the Transfer, has committed in writing to be bound by this
Agreement to the same extent and nature as the transferring Party;

     (2) No Transfer shall relieve the transferring Party of its share of any
liability, whether accruing before or after such Transfer, that arises out of
Operations conducted prior to such Transfer;

     (3) The transferring Party and the transferee shall bear all tax
consequences of the Transfer;


                                       27


     (4) No such Transfer shall occur within twenty-four (24) months from the
date of this Joint Venture Agreement, unless the Transfer is of a security
interest to secure a bona fide loan or other bona fide indebtedness; and

     (5) If the Transfer is the grant of a security interest by mortgage, deed
of trust, pledge, lien or other encumbrance of its interest in this Agreement,
to Secure a loan or other indebtedness of a Party in a bona fide transaction,
such security interest shall be subordinate to the terms of this Agreement and
the rights and the interests of the other Parties hereunder. Upon any
foreclosure or other enforcement of rights in the security interest, the
acquiring third party shall be deemed to assume the position of the encumbering
party with respect to this Agreement and the other Parties, and it shall comply
with the terms and conditions of this Article XV.

     15.3 Preemptive Right. Except as otherwise provided in Section 15.4, it a
Party desires to transfer all or part of its interest in this Agreement, the
other Party shall have a preemptive right to acquire such interest in addition
to such Party's right to reasonably withhold consent to the transfer under
Section 15.1.

         15.3.1 A Party intending to transfer all or part of its interest in
this Agreement shall promptly notify the other Party of its intentions. The
notice shall state the price and all other pertinent items and conditions,
including contingent payments and royalties, if applicable, of the intended
transfer, which shall be for a monetary consideration only. The other Party
shall have thirty (30) days from the date such notice is delivered to notify the
transferring Party whether it elects to acquire the offered interest at the same
price and on the same terms and conditions as set forth in the notice. If the
other Party so elects, the transfer shall be consummated within sixty (60) days
after notice of such election is delivered to the transferring Party.

     15.3.2 If the other Party does not elect within the period provided for in
Section 15.3.1, the transferring Party shall have ninety (90) days following the
expiration of such period to consummate the transfer to a third party at an
identical or greater price and on terms no less favorable to the transferring
party than those presented to the other Party and set forth in the notice
required in Section 15.3.1.

     15.3.3 If the transferring Party fails to consummate the transfer to
execute a binding agreement to transfer to a third party within the period set
forth in Section 15.3.2, or upon change in the price or terms offered to the
third party, the preemptive right of the other Party in such offered interest
shall be deemed to be revived. Any subsequent proposal to transfer such
interest shall be conducted in accordance with all of the procedures set forth
in this Section 15.3.

     15.4 Exceptions to Preemptive Right. Section 15.3 and the right of a Party
under Section 15.1 to reasonably withhold consent to a transfer shall not apply
to the following transfers:

     (1) Transfer by a Party of all or any part of its interest in this
Agreement to an Affiliate; or


                                       28


     (2) Incorporation of a Party or corporate merger, consolidation,
amalgamation of reorganization of a Party by which the surviving entity shall
possess substantially all of the stock, or all of the property rights and
interest, and be subject to substantially all of the liabilities and
obligations, including those created by this Agreement, of that Party; or

     (3) The grant by a Party of a security interest in its interest in this
Agreement by mortgage, deed of trust, pledge, lien or other encumbrance.

     15.5 Insolvency. If any Party commences a voluntary case under the federal
bankruptcy laws or under any other applicable federal or state law relating to
insolvency, if any order for relief or similar determination is entered in an
involuntary case under the federal bankruptcy laws or any other federal or state
law relating to insolvency, or if a receiver, liquidator, assignee, trustee,
custodian or other similar person is appointed voluntarily or involuntarily,
for the assets of any Party, then such Party (the "Insolvent Party") shall cease
to have the right to participate in the management of the Joint Venture, and the
Joint Venture thereafter shall be managed by the other Parties. In continuing to
manage the Joint Venture, the other Parties shall have absolute discretion and
no action taken by such other Parties shall subject such other Parties to a
claim for any breach of duty, on the ground of conflict of interest, negligence
or any other theory, except fraud or gross negligence. Any transfer, sale,
assignment, pledge or other encumbrance or disposition of the Insolvent Party's
interest in the Joint Venture by a trustee, debtor-in-possession or custodian
shall be subject to the provisions of Section 15.3.

                                   ARTICLE XVI

                               GENERAL PROVISIONS

     16.1 Notices. All notices, payments and other required communications
("Notices") to the Parties shall be in writing and shall be addressed
respectively as follows:

          NGVD

          If Mailed or Delivered:

               Natural Gas Vehicle Development Company Inc.
               2250 Cherry Industrial Circle
               Long Beach, California 90805
               Attn: Arthur L. Boschen

          If by Fax: 310-630-1382


                                       29


          ECA

          If Mailed or Delivered:

               EcoTrans Aftermarket Corporation
               2325 Crenshaw Blvd.
               Torrance, CA 90501-3335
               P.O. Box 2815
               Torrance, CA 90509-2815

               Attention: Mr. Detlef Stevenson, Vice President 

          If by Fax:  310-781-7250

          Copy to:

               Southern California Gas Company Law Department
               633 W. Fifth Street Suite 5400
               Los Angeles, CA 90071

               Attention: Mr. William A. Dorland 

          If by Fax: 213-629-9620

Copies of all Notices shall be given to the Manager at the Principal Office.

     All Notices shall be given: (1) by personal delivery to the Party; or (2)
by registered or certified mail, return receipt requested; or (3) by electronic
communication ("Fax") followed within 24 hours by acknowledgment of receipt from
the receiving Party. The term "electronic communication" includes but is not
limited to telex and facsimile communication. All Notices shall be effective and
shall be deemed delivered: (1) if by personal delivery, on the date of delivery;
(2) if by electronic communication, on the date the acknowledgment of receipt is
postmarked by the United States Postal Service; and (3) if solely by mail on the
day five (5) days after the date delivered, with postage prepaid and properly
addressed, to the United States Postal Service as shown on the actual Certified
Mail receipt.

     A Party may change its address from time to time by notice to the other
Party. Notice to the Management Committee shall be by notice to the Parties as
provided herein.

     16.2 Waiver. The failure of a Party to insist on the strict performance of
any provision of this Agreement or to exercise any right, power or remedy upon a
breach hereof shall not constitute a waiver of any provision of this Agreement
or limit that Party's right thereafter to enforce any provision or exercise any
right.


                                       30


     16.3 Modification. No modification of this Agreement shall be valid unless
made in writing and duly executed by all of the Parties nor, in any event,
through course of dealing, course of performance or usage of trades.

     16.4 Governing Law and Jurisdiction. This Agreement shall be governed by
and interpreted in accordance with the internal laws of the State of California.

     16.5 Rule Against Perpetuities. If any provision of this Agreement would
violate the rule against perpetuities or some analogous statutory provision, or
any other statutory or common law rule imposing time limits, then such provision
shall continue only until 21 years, less one day, after the death of the last
survivor of the individuals who executed this Agreement.

     16.6 Further Assurance. Each of the Parties agrees that it shall take from
time to time such actions and execute such additional instruments as may be
reasonably necessary or convenient to implement and carry out the intent and
purpose of this Agreement.

     16.7 Survival of Terms and Conditions. The provisions of this Agreement
shall survive its termination to the full extent necessary for their enforcement
and the protection of the Party in whose favor they run.

     16.8 Confidentiality and Public Statements. Except as otherwise provided in
this Section 16.8, the terms and conditions of this Agreement and all data,
reports, records and other information of any kind whatsoever developed or
acquired by any Party in connection with this Joint Venture shall be treated by
the Parties as confidential (hereinafter "confidential information") and no
Party shall reveal or otherwise disclose such confidential information to the
third parties without the prior written consent of the other Parties.
Advertising and promotion materials are to be approved by the Management
Committee prior to their use.

     The foregoing restrictions shall not apply to the disclosure of
confidential information to the following Persons on a need to know basis for
Joint Venture purposes, provided that reasonable steps are taken to insure that
such Persons shall also maintain the confidentiality of the confidential
information:

     (1) Any Affiliate;

     (2) Any Authorized Person;

     (3) Any public or private financing agency or institution;

     (4) Any contractors or subcontractors that the Parties may engage;

     (5) Employees and consultants of the Joint Venture or the Parties;


                                       31


     (6) Any third party to which a Party contemplates the transfer, sale,
assignment, encumbrance or other disposition of all or part of its Participating
Interest pursuant to Article XV; provided, however, that in any such case only
such confidential information as such third party shall have a legitimate
business need to know shall be disclosed;

     (7) Confidential information that otherwise comes into the public domain;
or 

     (8) Confidential information that is required, in any Party's reasonable
opinion, to be disclosed to any federal, state or local government or
appropriate agencies and departments thereof or that is required, in any Party's
reasonable opinion, to be publicly announced, to the extent required by law,
rules, regulations or order of any such body.

     The provisions of this Section 16.8 shall apply during the term of this
Agreement and shall continue to apply to any Party that forfeits, surrenders,
assigns, transfers or otherwise disposes of its Participating Interest for the
two-year period following the date of such occurrence.

     Except as otherwise provided herein, no Party to this Agreement shall make
any public announcement or public disclosure with regard to the Joint Venture,
including confidential information without the prior written consent of the
other Parties as to the content and timing of such announcement or disclosure,
which shall not be unreasonably withheld.

     16.9 Notice of Claim. Promptly after a Party learns of any event,
condition, circumstance, or a claim relating thereto, that has resulted, or may
result in a claim, liability, or cause of action of any kind against the Joint
Venture, or if any Party is sued or receives notice of a suit on an alleged
claim or cause of action arising out of Joint Venture operations, such Party
shall give notice to the other Parties.

     16.10 Entire Agreement. This Agreement, including all attached Exhibits,
contains the entire understanding of the Parties and supersedes all prior
agreements and understandings between the Parties related to the subject matter
hereof.

     16.11 Successors and Assigns. This Agreement shall be binding upon and
inure to the benefit of the respective successors and permitted assigns of
the Parties.

     16.12 Memorandum. At the request of any Party, a short form of this
Agreement, which shall not disclose financial information contained herein,
shall be prepared and recorded by the Manager. This Agreement shall not be
recorded.

     16.13 Use of Singular and Plural. As used in this Agreement and where the
context so requires, the singular shall be deemed to include the plural and the
plural shall be construed as the singular.

     16.14 Counterparts. This Agreement may be executed in one or more
counterparts, each of which will be deemed an original but all of which together
will constitute one and the same instrument.


                                       32


     IN WITNESS WHEREOF, the Parties hereto have executed this Agreement as of
the date first above written.

NATURAL GAS VEHICLE DEVELOPMENT            EcoTrans Aftermarket Corporation
COMPANY INC.



By: /s/ Arthur L. Boschen                  By: /s/ Wilton E. Miller
   -----------------------------------        ----------------------------------
   Title: Arthur L. Boschen, President        Title: Wilton E. Miller, President


                                       33


                               AMENDMENT NO. 1 TO
                             JOINT VENTURE AGREEMENT

     This Amendment No. 1 to Joint Venture Agreement (the "Amendment") is made
as of this 14 day of December, 1995, by and between Natural Gas Vehicle
Development Company Inc., a California corporation ("NGVD"), and EcoTrans
Aftermarket Corporation, a California corporation ("ECA"), amending the
Agreement referred to below. Unless otherwise defined herein, all capitalized
terms used herein shall have the same meanings as specified in the Agreement.

                                    RECITALS

     WHEREAS, NGVD and ECA are parties to that certain Joint Venture Agreement
dated as of May 1, 1993 (the "Agreement");

     WHEREAS, NGVD and ECA desire to amend the Agreement as provided herein.

                                    AGREEMENT

     NOW, THEREFORE, NGVD and ECA agree as follows:

     1. Section 2.10(1) of the Agreement shall be amended in its entirety to
provide as follows:

          "(1) The Joint Venture's Staff will include the Manager, an Operations
     Manager (if appointed pursuant to Section 6.5), a controller and such
     mechanics, technicians, and support personnel as are necessary to carry out
     the business purposes of the Joint Venture efficiently and profitably."

     2. Section 5.1 of the Agreement shall be amended in its entirety to provide
as follows:

          "5.1 Organization and Composition. The Parties shall conduct the
     business of the Joint Venture through a Management Committee, which shall
     determine overall policies, objectives, procedures, methods and actions
     under this Agreement. NGVD and ECA shall each appoint two members to the
     Management Committee; provided, however, that if the Participating
     Interests of ECA shall become greater than 50%, but less than 75%, then ECA
     shall appoint three members to the Management Committee and NGVD shall
     appoint only one member to the




     Management Committee. Each Party may appoint one or more alternates to act
     in the absence of a regular member. Any alternate so acting shall be deemed
     to be a member. Appointments shall be made or changed by written notice to
     the other Party. Each Management Committee member may bring such technical
     and other advisors as it deems appropriate to all Management Committee
     meetings."

     3. Section 5.2 of the Agreement shall be deleted in its entirety through
December 31,1997 and reinstated thereafter.

     4. The first sentence of the last paragraph of Section 5.4 of the Agreement
shall be deleted in its entirety.

     5. Section 5.6(10) of the Agreement shall be amended in its entirety to
provide as follows:

          "(10) Selection of Manager and Controller, subject to the provisions
     of Section 6.1; and".

     6. Section 6.1 of the Agreement shall be amended in its entirety to provide
as follows:

          "6.1 Appointment. For the period commencing on the date hereof and
     continuing until December 31,1997, ECA shall be the Manager. From and after
     December 31,1997, the Management Committee may, upon review, select a
     replacement Manager. The Manager shall have overall, day-to-day
     responsibility for all Operations of the Joint Venture, including the
     powers and duties set forth in Section 6.2. The Manager shall serve in such
     capacity until he resigns or is replaced by the Management Committee. The
     Parties direct the Manager to perform the duties of the Manager of the
     Joint Venture subject to the terms and conditions of this Agreement. The
     Parties agree that at all times the Manager shall be the agent of the Joint
     Venture for conducting Operations on behalf of the Joint Venture and for
     the performance of such other duties as are imposed on the Manager by the
     Parties under or pursuant to the provisions of this Agreement. The Manager
     shall consult freely with the Management Committee."

     7. Section 6.2(8) of the Agreement shall be amended in its entirety to
provide as follows:

          "(8) Preside over all Management Committee meetings and prepare and
     maintain minutes of all Management Committee meetings and related
     correspondence." 


                                       2


     8. A new last sentence shall be added to Section 6.3 of the Agreement as
follows:

          "Subject to the approval of the Management Committee, in the event the
     Manager engages Affiliates of the Parties to provide services in the
     conduct of the Joint Venture and such Affiliates remain as employees of and
     are paid by the applicable Party, the Joint Venture shall reimburse the
     appropriate Party for all such expenses."

     9. Section 6.4 of the Agreement shall be amended in its entirety to provide
as follows:

          "6.4 Standard of Care and Liability. The Manager shall conduct the
     Operations and perform all of the obligations of Manager in a workmanlike
     and commercially reasonable manner, using prudent business judgment for the
     benefit of the Joint Venture. The Manager shall not be liable to the
     Parties for any action taken or the failure to act in connection with the
     duties and powers of the Manager provided herein, except in the case of
     gross negligence or willful misconduct."

     10. A new Section 6.5 shall be added to the Agreement to provide as
follows:

          "6.5 Operations Manager. The Manager may appoint an Operations Manager
     to carry out such powers and duties of the Manager as the Manager may
     delegate to the Operations Manager. The Operations Manager shall report
     directly to the Manager. The Operations Manager shall receive compensation
     for the performance of such duties in an amount to be determined by the
     Manager with the consent of the Management Committee."

     11. Section 12.1 of the Agreement shall be amended in its entirety to
provide as follows:

          "12.1 Events of Default. The following events shall constitute events
     of default:

               (1) Any transfer by a Party of any part of its interest in the
          Joint Venture in contravention of the provisions of Article XV;

               (2) Failure of a Party to make any portion of an Equity
          Contribution when due;

               (3) Failure of a Party to perform any other obligation imposed
          upon such Party by this Agreement;


                                       3


               (4) Filing of a petition in bankruptcy by or against a Party, or
          any person or entity directly or indirectly controlling Party, if such
          petition is not withdrawn or dismissed within sixty (60) days after
          its filing;

               (5) Assignment by a Party, or any person or entity directly or
          indirectly controlling Party, for the benefit of creditors; or

               (6) Allowance by a Party, or any person or entity directly or
          indirectly controlling Party, of the appointment of a receiver or
          trustee for all or any part of its property if such receiver or
          trustee is not discharged within sixty (60) days after his
          appointment.

     12. Section 15.5 of the Agreement shall be amended in its entirety to
provide as follows:

          "15.5 Insolvency. If any Party, or any person or entity directly or
     indirectly controlling Party, commences a voluntary case under the federal
     bankruptcy laws or under any other applicable federal or state law relating
     to insolvency, if any order for relief or similar determination is entered
     in an involuntary case under the federal bankruptcy laws or any other
     federal or state law relating to insolvency, or if a receiver, liquidator,
     assignee, trustee, custodian or other similar person is appointed,
     voluntarily or involuntarily, for the assets of any Party, or any person or
     entity directly or indirectly Party, then such Party (the "Insolvent
     Party") shall cease to have the right to participate in the management of
     the Joint Venture, and the Joint Venture thereafter shall be managed by the
     other Party. In continuing to manage the Joint Venture, the other Party
     shall have absolute discretion and no action taken by such other Party
     shall subject such other Party to a claim for any breach of duty, on the
     ground of conflict of interest, negligence or any other theory, except
     fraud or gross negligence. Any transfer, sale, assignment, pledge or other
     encumbrance or disposition of the Insolvent Party's interest in the Joint
     Venture by a trustee, debtor-in-possession or custodian shall be subject to
     the provisions of Section 15.3."

     13. Unless the context otherwise requires, all references to the Agreement
shall mean the Agreement as amended hereby.

     14. This Amendment may be executed in one or more counterparts, all of
which taken together shall constitute one agreement and any party hereto may
execute this Amendment by signing any such counterpart.


                                       4


     15. Except as provided herein, all provisions, terms and conditions of the
Agreement shall remain in full force and effect. As amended hereby, the
Agreement is ratified and confirmed in all respects.

     IN WITNESS WHEREOF, NGVD and ECA have caused this Amendment to be executed
and delivered by their duly authorized officers as of the day and year first
above written.

                                       NATURAL GAS VEHICLE DEVELOPMENT 
                                       COMPANY, a California corporation



                                       By /s/ John R. Bacon
                                         -------------------------------------
                                         Title: President


                                       ECOTRANS AFTERMARKET CORPORATION,
                                       a California corporation


                                       By /s/ [Illegible] 
                                         -------------------------------------
                                         Title: Vice President


                                       5


                                 AMENDMENT NO. 2
                                       TO
                             JOINT VENTURE AGREEMENT

          This Amendment No. 2 to Joint Venture Agreement (the "Amendment") is
made and shall become eftective as of the first day of January, 1996, by and
among Natural Gas Vehicle Development Company, a California corporation
("NGVD"), EcoTrans OEM Corporation, a California corporation ("OEM", formerly
known as EcoTrans Aftermarket Corporation), and Cardinal Automotive Incorporated
("CAI"). Unless otherwise specified herein, all references are to the Agreement
(as defined in the first paragraph of the Recitals) and initially capitalized
terms used herein shall have the same meanings as specified in the Agreement

                                    RECITALS

          WHEREAS, NGVD and OEM's predecessor in interest, EcoTrans Aftermarket
Corporation, are Parties to the Joint Venture Agreement dated as of May 1, 1993,
as amended by Amendment No. 1, dated as of December 14, 1995 (as so amended, the
"Agreement");

          WHEREAS, CAI wishes to become, and NGVD and OEM wish to admit CAI as,
a member of the Joint Venture and a Party to the Agreement on the terms and
conditlons specified in this Amendment;

          WHEREAS, OEM and CAI wish to make further contributions to the capital
of the Joint Venture on the terms and conditions specified in this Amendment,
resulting in a corresponding adjustment to the interests of all Parties so that
NGVD will have a 35% interest, CAI will have a 15% interest, and OEM will have a
50% interest; and

          WHEREAS, NGVD, CAI and OEM desire to make conforming amendments to the
Agreement and to continue the business of the Joint Venture as a Limited
Liability Company organized under the laws of Delaware.

                                    AGREEMENT

          NOW, THEREFORE, NGVD, OEM and CAI agree as follows:

          1. Article I is amended by adding the following definitions

               "1.32 "CAI" means Cardinal Automotive Incorporated, a Michigan
     corporation.

               1.33 "OEM" means EcoTrans OEM Corporation, a CAIifornia
     corporation, formerly known as "EcoTrans Aftermarket Corporation" or "ECA",
     with its principal offices at 555 West Fifth Street, Los Angeles,
     CAIifornia 90013-1011."

          2. Substitute "OEM" for "ECA" throughout the Agreement.

          3. Section 2.1 of Article II is amended in its entirety to provide as
follows:

               "2.1 Reorganization as a Limited Liability Company.



                    (a) The Parties hereby reorganize the Joint Venture as a
     limited liability company under the laws of the State of Delaware for the
     limited purposes and scope set forth herein. Such reorganization shall be
     effective as of January 1, 1996, or as soon thereafter as a Certificate of
     Formation has been duly filed in the Office of the Secretary of State of
     Delaware in the form required by law. The parties intend that the Joint
     Venture continue to be construed as a partnership or "flow through" tax
     organization for purposes of federal, state and other taxes.

                    (b) The Joint Venture shall possess and may exercise all the
     powers and privileges granted under, and its internal affairs shall be
     governed by, the laws of Delaware pertaining to limited liability
     companies, except as expressly limited by this Agreement.

                    (c) The liability of each Party for daims and obligations
     relating to the Joint Venture and its activities is expressly limited to
     its Equity Contribution to the fullest extent permitted by law. Without its
     express written consent, upon the making of its Equity Contribution no
     Party shall be required, through arbitration or otherwise, to make any
     additional contributions, advances or loans to, or to pay or guarantee any
     obligations or indebtedness of, the Joint Venture except as expressly
     provided in Article XIII of this Agreement

                    (d) As is more fully specified in Section 6.1, OEM's
     designated representative shall act as Manager of the Joint Venture until
     resignation or replacement.

                    (e) The Assets shall be held in the Joint Venture name and
     not in the names of the individual Parties, and no Party shall have any
     individual ownership in such property except for its property rights as a
     Party to this Joint Venture.

                    (f) All agreements, permits and transactions regarding the
     Assets shall be executed and performed by the Joint Venture in its own name
     and not in the names of the individual Parties.

                    (g) The Joint Venture shall operate in accordance with the
     terms and conditions of this Agreement."

          4. Section 2.2 of Article II is amended by the addition of the
following first sentence:

               "2.2 Name and Principal Place of Business The name of the Joint
Venture shall be 'NGV EcoTrans Group, L.L.C."

          5. Article III is amended by adding the following sections

               "3.7 OEM's Additional Contributions. Prior to January 10, 1996,
     OEM shall deliver to the capital of the Joint Venture the in-kind
     contributions described on Schedule 1, which is attached hereto and
     incorporated by reference herein as though fully set forth. Such in-kind
     contributions have an agreed value in excess of $200,000 and shall be free
     and clear of all liens and encumbrances, except as specified on Schedule 1.

               3.8 CAI's Contributions. Prior to January 10, 1996, CAI shall
     deliver to the capital of the Joint Venture the in-kind contributions
     described on Schedule 2, which is attached hereto and incorporated by
     reference herein as though fully set forth. Such nkind contributions have
     an agreed value in excess of $200,000 and shall be free and clear of all
     liens and encumbrances, except as specified on Schedule 2."

                                        2


          6. Section 4.1 of Article IV is amended in its entirety to provide as
follows:

               "4.1 Participating Interests. The Participating Interests of the
     Parties in the profits, losses and assets of the Joint Venture shall be:

            NGVD:  Thirty-Five Percent (35%)

            CAI:   Fifteen Percent (15%)

            OEM:   Fifty Percent (50%)"

          7. Section 5.1 of Article V is amended in its entirety to provide as
follows:

               "5.1 Organization and Composition. The Parties shall conduct the
     business of the Joint Venture thmugh a Management Committee, which shall
     determine overall policies, objectives, procedures, methods and actions
     under this Agreement. NGVD and OEM shall each appoint two members to the
     Management Committee and CAI shall appoint one member. Each Party may
     appoint one or more alternates to act in the absence of a regular member.
     Any alternate so acting shall be deemed to be a member. Appointments shall
     be made or changed by written notice to the other Parties. Each Management
     Committee member may bring such techniCAI and other advisors as it deems
     appropriate to all Management Committee meetings."

          8. Section 5.2 of Article V is deleted in its entirety.

          9. Section 5.3 and the first two paragraphs of Section 5.4 of Article
V are amended in their entirety to provide as follows:

               "5.3 Decisions. Each Party shall vote and act through its
     appointed members on the Management Committee, unless otherwise provided in
     this Agreement. Decisions made by the Management Committee shall be by a
     vote of sixty-five percent (65%) of the Participating Interests of the
     Joint Venture. In the event of an impasse having a materially adverse
     effect on Joint Venture operations, the matter shall be determined by
     binding arbitration in accordance with Section 12.4; provided, however,
     that, without its express written consent, no Party shall be required,
     through arbitration or otherwise, to make any additional contributions,
     advances or loans to, or to pay or guarantee any obligations or
     indebtedness of, the Joint Venture except as expressly provided in this
     Agreement.

               5.4 Meetings. Unless otherwise agreed, the Manager shall give the
     Parties thirty (30) days notice of meetings of the Management Committee,
     but receipt by all Parties of such thirty (30) day notice shall not be a
     prerequisite for the holding of a regular meeting. Any Party may call a
     special meeting upon ten (10) days notice to the other Parties. In case of
     emergency, reasonable notice shall suffice.

               Notice may be waived by the written consent of the Management
     Committee members. A quorum for any meeting shall consist of one member
     representing each Party. However, if any Party fails to attend two
     consecutive properly called meetings, then a quorum shall consist of the
     member or members representing the other Party(s) and such Party(s) vote
     shall be considered the vote required by Section 5.3 for the purposes of
     the conduct of all business properly noticed."

          10. Section 6.1 of Article VI is amended in its entirety to provide as
follows:

               "6.1 Appointment. OEM shall designate one of its representatives
     as Manager. The Manager shall have overall, day-to-day responsibility for
     all

                                        3


     Operations of the Joint Venture, including the powers and duties set forth
     in Section 6.2. The Manager shall serve in such capacity until resignation,
     replacement by OEM or replacement by vote of the Management Committee in
     accordance with Section 5.3 of this Agreement. The Parties direct the
     Manager to perform the duties of Manager of the Joint Venture subject to
     the terms and conditions of this Agreement. The Parties agree that at all
     times the Manager shall be the agent of the Joint Venture for conducting
     Operations on behalf of the Joint Venture and for the performance of such
     other duties as are imposed on the Manager by the Parties under or pursuant
     to the provisions of this Agreement. The Manager shall consult freely with
     the Management Committee."

          11. Article X, Insurance, is amended by substituting "NGVD, CAI and
OEM" for "NGVD and ECA" throughout.

          12. Section 12.6 of Article XII is amended in its entirety to provide
as follows:

               "12.6 Non-Recourse Obligations

                    (a) All obligations of OEM hereunder shall be the sole
     responsibility of OEM and, in the absence of any express written assumption
     thereof, neither NGVD, CAI nor any person or entity on behalf of any of
     them shall have any recourse to any person or entity other than OEM
     (including, but not limited to OEM's shareholders, officers, directors or
     employees or its affiliates) for any breach by or liability of OEM arising
     out of this Agreement. Without diminishing the generality of the foregoing,
     the parties agree that Southern California Gas Company and Pacific
     Enterprises shall have no obligations or liabilities whatsoever under, or
     arising out of, this Agreement.

                    (b) All obligations of NGVD hereunder shall be the sole
     responsibility of NGVD and, in the absence of any express written
     assumption thereof, neither OEM, CAI nor any person or entity on behalf of
     any of them shall have any recourse to any person or entity other than NGVD
     (including, but not limited to NGVD's shareholders, officers, directors or
     employees or its affiliates) for any breach by or liability of NGVD arising
     out of this Agreement.

                    (c) All obligations of CAI hereunder shall be the sole
     responsibility of CAI and, in the absence of any express written assumption
     thereof, neither OEM, NGVD nor any person or entity on behalf of any of
     them shall have any recourse to any person or entity other than CAI
     (including, but not limited to CAI's shareholders, officers, directors or
     employees or its affiliates) for any breach by or liability of CAI arising
     out of this Agreement."

          13. Article XII, Indemnification, is amended in its entirety to
provide as follows:

               "13.1 Indemnification of Manager by Joint Venture. The Joint
     Venture shall indemnify, defend and hold harmless the Manager and the Party
     designating the Manager (including such Party's officers, directors,
     employees and agents) from any and all claims, expenses, costs (including
     reasonable attorneys fees), loss and liability arising out of or connected
     with Manager's performance under this Agreement, provided that Manager was
     acting in good faith and in what (s)he believed to be the best interests of
     the Joint Venture.

               13.2 Indemnification of Joint Venture by Party Designating
     Manager. The Party designating the Manager shall indemnify, defend and hold
     harmless the Joint Venture from any and all claims, expenses, costs
     (including reasonable attorneys fees), loss and liability arising out of or
     connected with Manager's failure to

                                        4


     act in good faith and in what (s)he believed to be the best interests of
     the Joint Venture.

               13.3 Indemnification of Joint Venture by all Parties. Each Party
     shall indemnify, defend and hold harmless the Joint Venture and the other
     Parties from any and all claims, expenses, costs (including reasonable
     attorneys fees), loss and liability arising out of or connected with the
     Joint Venture caused by the gross negligence, willful misconduct, breach of
     warranty, or unauthorized binding of the Joint Venture to an obligation by
     such Party or its Affiliate; provided that this provision shall not extend
     to claims, expenses, costs, loss and liability arising out of the provision
     of products by a Party or Affiliate which are used by the Joint Venture in
     the conversion of vehicles to natural gas power, as such products are
     covered by separate warranties.

               13.4 Additional Provisions. The obligations of the Parties
     pursuant to the provisions of Sections 13.1, 13.2 and 13.3 are subject to
     the following additional rights and limitations:

                    13.4.1 The indemnification provided for by this Article XIII
     available to a Party shall extend to an Affiliate of that Party with
     respect to claims, expenses, costs (including reasonable attorneys fees),
     loss and liability arising out of a Joint Venture liability or obligation
     that is paid by or incurred by such Affiliate solely as a result of such
     Affiliate directly or indirectly owning or controlling the Party.

                    13.4.2 The indemnification provided for by this Article XIII
     shall not inure to the benefit of any Party or Affiliate in respect of any
     claims, expenses, costs (including reasonable attorneys fees), loss or
     liability to the extent that they

                         (a) Are a tax, levy or similar fee or governmental
     charge which is not imposed upon the Joint Venture or upon its Assets;

                         (b) Arise out of, or is based upon, the gross
     negligence, willful misconduct, breach of warranty, or unauthorized binding
     of the Joint Venture to an obligation by the Party or Affiliate seeing to
     be indemnified;

                         (c) Are covered by the insurance (exclusive of
     self-insurance) of the Party or Affiliate seeking to be to be indemnified."

          14. Section 14.1 of Article XIV is amended in its entirety to provide
as follows:

               "14.1 The Joint Venture is dissolved and its affairs shall be
     wound up upon the first to occur of the following:

                    14.1.1 Termination by Agreement. The Parties may dissolve
     this Joint Venture at any Ume by written agreement.

                    14.1.2 Termination by Expiration. The Joint Venture shall be
     dissolved on January 1, 2026, unless, to the extent permitted by law, the
     business of the Joint Venture is continued by the consent of all Parties.

                    14.1.3 Termination by Disability. The Joint Venture shall be
     dissolved upon the death, retirement, resignation, expulsion, bankruptcy or
     dissolution of a Party or the occurrence of any other event which
     terminates the continued membership of a Party in the Joint Venture unless
     the business of the Joint Venture is continued by the consent of all the
     remaining Parties within ninety (90) days following the occurrence of any
     such event.

                                        5


                    14.1.4 Termination by Arbitration Decision or Judicial
     Decree. The Joint Venture shall be dissolved for cause pursuant to
     applicable law, if requested by a Party and required by a duly issued
     decision of a board of arbitrators properly convened pursuant to Section
     12.4 or ordered by a court of competent jurisdiction."

          15. Section 15.1 of Article XV shall be amended in its entirety to
provide as follows:

               "15.1 Consent to Transfer Participating Interest. Upon the
     written consent of the remaining Parties, a Party may assign or transfer
     all or a portion of its interest in the Joint Venture and the assignee or
     transferee shall become a substitute member of the Joint Venture.
     Notwithstanding the foregoing, a Party may grant a security interest in its
     Participating Interest by mortgage, deed of trust, pledge, lien or other
     encumbrance in a bona fide transaction, provided that, except as may be
     agreed by the remaining Parties, such security interest is subordinate to
     the terms of this Agreement and the rights and interests of the other
     Parties hereunder and that upon any foreclosure or other enforcement of
     rights in the security interest, the acquiring third party shall be deemed
     to acquire only the right to receive any distributions from the Joint
     Venture to which the transferring party would be entitled (absent such
     security interest) and shall not thereby have any right to participate in
     the management or operation of the Joint Venture through membership in the
     Management Committee or otherwise."

          16. Article XV, Transfer of Interest, is further amended by deleting
clause (5) of Section 15.2 and deleting Sections 15.3, Preemptive Right, and
15.4, Exceptions to Preemptive Right.

          17. Section 16.1, Notices, of Article XVI is amended by Substituting
the name "Mr. John Weber" for that of "Mr. Detlef Stevenson" and by adding the
following address for notice for CAI:

                       "Cardinal Automotive Incorporated

                        7200 FIFTEEN MILE RD.           
                        STERLING HEIGHTS MI
                                      48312-4525
                        If by Fax:  810-268-6488"
                        
          18. Unless the context otherwise requires, all references to the
Agreement shall mean the Agreement as amended hereby and all references in the
Agreement to the singular shall include the plural and vice versa.

          19. This Amendment may be executed in one or more counterparts, all of
which taken together shall constitute one agreement any Party may execute this
Amendment by signing any such counterpart.

          20. Except as provided herein, all provisions, terms and conditions of
the Agreement, as previously amended, shall remain in full force and effect. As
hereby amended, the Agreement is ratified and confirmed in all respects.


                                        6



          IN WITNESS WHEREOF, NGVD, CAI and OEM have caused this Amendment to be
executed and delivered by their duly authorized officers this __ day of
December, 1995, provided that this Amendment shall become eftective as of the
first Day of January, 1996.



NATURAL GAS VEHICLE                     CARDINAL AUTOMOTIVE 
DEVELOPMENT COMPANY,                    INCORPORATED, 
a corporation                           a corporation 


By /s/ John R. Bacon                    By /s/ Todd W. Rogers
  ---------------------------             --------------------------
Title President                         Title President
     ------------------------                -----------------------



ECOTRANS OEM CORPORATION,
a corporation


By Warren I. Mitchell
  ---------------------------
Title President              
     ------------------------




Attachments:  Schedule 1 - Additional Capital Contribution of OEM (Section 3.7) 
              Schedule 2 - Additional Capital Contribution of CAI (Section 3.8)


                                       7



                                                            [STAMP]
December 20, 1995                                           RECEIVED
                                                            DEC 20 1995
To: John Bacon, Todd Rogers, John Weber

From: Ron Smith

Subject: Changes to Amendment 2


The following represent changes to Amendment 2 following yesterday's meeting
between John Bacon and John Weber.

     References to "Manager" are clarified so as to refer to OEM's Designated
Manager, and Individual. (2.1(d), 8.1, 13.1 and 13.2)

     5.1 has been amended to limit CAI to one Management Committee member.

     5.2 is expressly deleted (under Amendment 1, it would "spring" into 
validity in 1997)

     14.1.4 has been clarified

     18 defines singular to include the plural, to cover the many references
in the JV to the "other Party."

If there is any questions or concerns please let me know by pager 213-968-6162.



                                 AMENDMENT NO.3
                                       TO
                             JOINT VENTURE AGREEMENT

          This Amendment No.3 to Joint Venture Agreement (the "Amendment") is
made and shall become effective as of the first day of January, 1996, by and
among Natural Gas Vehicle Development Company, a California corporation
("NGVD"), EcoTrans OEM Corporation, a California corporation ("OEM", formerly
known as EcoTrans Aftermarket Corporation), and Cardinal Automotive Incorporated
("CAI").

                                    RECITALS

          WHEREAS, NGVD, OEM and CAI have entered into Amendment No. 2, dated as
of January 1, 1996 ("Amendment 2"), which amends that certain Joint Venture
Agrement dated as of May 1, 1993, as previously amended (as so amended, the
"JVA" or "Agreement"); and

          WHEREAS, NGVD, OEM and CAI desire to further clarify Amendment 2.

                                    AGREEMENT

          NOW, THEREFORE, NGVD, OEM and CAI agree as follows:

1.   Section 9 of Amendment 2 (amending Section 5.3 of the JVA) is amended by
     substituting "unanimous vote" for "vote of sixty-five percent (65%)".

2.   Section 10 of Amendment 2 (amending Section 6.1 of the JVA) is amended by
     rephrasing the first sentence of Section 6.1 of the Agreement, as thereby
     amended, to provide as follows:

          "OEM shall designate one of its representatives as Manager, to serve
          for an initial term of three (3) years, through January 1, 1999,
          whereupon the Management Committee will have the right to approve the
          Manager by unanimous vote in accordance with Section 5.3 of this
          Agreement."

3.   Section 13 of Amendment 2 (amending Article XIII of the JVA) is amended by
     deleting the proviso "as such products are covered by separate warranties"
     at the end of Section 13.3 and adding the following provision as 
     Section 13.4.3:

          "13.4.3 Neither a Party nor the Joint Venture shall be liable by
          reason of this Article XIII for any claims, expenses, costs, loss or
          liability arising out of the provision of products by such Party or an
          Affiliate or by the Joint Venture which are used by the Joint Venture
          in the conversion of vehicles to natural gas power; provided that
          nothing herein shall deprive a Party, an Affiliate, the Joint Venture,
          or any other natural person or entity of remedies to which it would be
          entitled in the absence of the foregoing provisions of this Article
          XIII."



4.   Section 15 of Amendment 2 (amending Section 15.1 of the JVA) is modified by
     amending tne first sentence thereof to provide as follows:

          "Upon the written consent of the remaining Parties, which shall not be
          unreasonably withheld, a Party may assign or transfer all or a portion
          of its interest in the Joint Venture, and the assignee or transferee
          shall become a substitute member of the Joint Venture."

5.   Section 16 of Amendment 2 (further amending Article XV of the JVA), is
     amended to reinstate the preemptive rights of the Parties (in proportion to
     their Participating Interests) by amending that section to provide as
     follows:

          "16. Article XV, Transfer of Interest, is further amended by deleting
          clause (5) of Section 15.2."

6.   Section 17 of Amendment 2 (amending Section 16.1 of the JVA) is amended by
     adding the following addresses for notice:

                   Cardinal Automotive Incorporated
                   Attn: Mr. Todd Rogers, President
                   7200 Fifteen Mile Road
                   Sterling Heights, MI 48312-4525

                   If by fax: (810) 268-6488


                   Natural Gas Vehicle Development Company
                   Attn: Mr. John R. Bacon, President
                   5580 Cherry Avenue
                   Long Beach, CA 90805

                   If by fax: (310) 630-1382

7.   Attached hereto are corrected Schedules 1 and 2, which shall be inserted in
     the Agreement as attachments to Amendment 2.

8.   This Amendment may be executed in one or more counterparts, all of which
     taken together shall constitute one agreement. Any Party may execute this
     Amendment by signing any such counterpart.

9.   Except as provided herein, all provisions, terms and conditions of the
     Agreement, as previously amended, shall remain in full force and effect. As
     hereby amended, the Agreement is ratified and confirmed in all respects.


                                        2



     IN WITNESS WHEREOF, NGVD, CAI and OEM have caused this Amendment to be
executed and delivered by their duly authorized officers this ___ day of
December, 1995, provided that Amendment 2, as modified by this Amendment, shall
become effective as of the first day of January, 1996.



NATURAL GAS VEHICLE                     CARDINAL AUTOMOTIVE 
DEVELOPMENT COMPANY,                    INCORPORATED, 
a corporation                           a corporation 


By /s/ John R. Bacon                    By /s/ Todd W. Rogers
  ---------------------------             --------------------------
Title President                         Title President
     ------------------------                -----------------------



ECOTRANS OEM 
CORPORATION,
a corporation


By John Weber
  ---------------------------
Title Vice President         
     ------------------------


                                       3



                                   SCHEDULE 1

                            OEM EQUITY CONTRIBUTION

1. Fixtures and assets in building #3 or NGV Ecotrans' building that remain on
loan. Estimated value $200,000.

     A. Cylinder hoists in both buildings

     B. Vehicle hoists totaling 6 and located in both buildings

     C. Computer systems including CAD systems located in both buildings

     D. Phones and furniture located in both buildings

     E. Gasoline siphoning pump system (pumps, piping, installation and permits)

     F. Air Compressor, FRLs and auxiliary lines installed in 1994 and 1995
        in bldg. #3

     G. Roll up doors on the dyno area in building #3

     H. New forklift converted to natural gas



                                   SCHEDULE 2

                          CARDINAL EQUITY CONTRIBUTION

1. Current backlog in excess of $1.5 million and 3% net profit of $45,000.

2. Expertise and goodwill established in S. California at $50K.

     A. Established ship-to codes for 2424E. Olympic Blvd.

     B. Experience and rapport established with a different set of customers
        than NGV Ecotrans.

     C. Industry recognition, Chrysler's Penastar quality award and resulting
        Business from Chrysler for Cardinal - Western Operations. Ford's QVM 
        approval in Detroit.

     D. Already established as an Impco/GM qualified upfitter through Feb. 1994
        with the former GM program.

3. Current management and production philosophies at $50K.

4. Cardinal assets estimated at less than $50K.



                [LETTERHEAD OF LINDABURY, McCORMICK & ESTABROOK]

                                December 28, 1995

Via Facsimile

Mr. William Dorland
Pacific Enterprises Companies
P.O. Box 60043
M.L. 52M
Los Angeles, California 90060

               Re: Natural Gas Vehicle Development Company, Inc.

Dear Mr. Dorland:

     Please be advised that John Bacon has signed the Amendment No. 3 (the
"Amendment") to Joint Venture Agreement with one minor clarification. Paragraph
3 of the Amendment has been amended to read as follows:

     "Section 13 of Amendment 2 (amending Article XIII of the JVA) is amended by
     deleting the proviso. 'as such products are covered by separate warraties',
     at the end of Section 13.3 and adding the following provision as Section
     13.4.3:..."

     If you have any questions, please do not hesitate to contact me.
Unfortunately, I will be out of the office for the remainder of Thursday,
December 28, 1995, but I will be in my office tomorrow. Thank you.


                                             Very truly yours,

                                   LINDABURY, McCORMICK & ESTABROOK

                                             /s/ Colleen D. Brennan
                                             Colleen D. Brennan



CDB:ms
CC: John Bacon