1
                                                                  EXHIBIT 5.1(a)



                      [LETTERHEAD OF O'MELVENY & MYERS LLP]




                                January 11, 2001




Nissan Auto Receivables Corporation
Nissan Auto Receivables Corporation II
Nissan Motor Acceptance Corporation
Nissan Auto Receivables Trusts
990 West 190th Street
Torrance, California 90502

               Re:    Nissan Auto Receivables Corporation
                      Nissan Auto Receivables Corporation II
                      Nissan Motor Acceptance Corporation
                      Nissan Auto Receivables Trusts
                      Registration Statement on Form S-3
                      Registration No. 333-51224
                      Registration No. 333-51224-01

Ladies and Gentlemen:

               We have acted as special counsel to Nissan Auto Receivables
Corporation ("NARC") and Nissan Auto Receivables Corporation II ("NARC II"),
each a Delaware corporation and wholly owned limited purpose subsidiary of
Nissan Motor Acceptance Corporation ("NMAC"), a California corporation, and
certain trusts, all of the beneficial ownership of which will initially be owned
by NARC or NARC II (together with NARC and NARC II, each an "Issuer"), in
connection with the proposed issuance of $8,500,000,000 aggregate principal
amount of asset-backed notes (the "Notes") to be offered pursuant to a
registration statement on Form S-3 (such registration statement, as amended, the
"Registration Statement") relating to the Notes. The Registration Statement has
been filed with the Securities and Exchange Commission under the Securities Act
of 1933, as amended (the "1933 Act"), and the rules and regulations promulgated
thereunder. The Notes for each series will be issued under and pursuant to an
indenture between the applicable Issuer and the Indenture Trustee (as defined
therein). The indenture in the form filed with the Securities and Exchange
Commission on January 11, 2001, as an exhibit to the Registration Statement, is
herein referred to as the "Indenture."

               We have examined originals or copies, certified or otherwise
identified to our satisfaction, of the organizational documents of the Issuers,
the Indenture, the form of Notes

   2

included as an exhibit to the Indenture, and such other records, documents and
certificates of the Issuers and public officials and other instruments as we
have deemed necessary for the purpose of this opinion. In addition, we have
assumed that the Indenture as completed for each series will be duly executed
and delivered by the parties thereto; that the Notes as completed for each
series will be duly executed and delivered substantially in the forms
contemplated by the Indenture; and that the Notes for each series will be sold
as described in the Registration Statement.

               Based upon the foregoing, we are of the opinion that:

               The Notes are in due and proper form and, assuming the due
authorization, execution and delivery of the Indenture by the applicable Issuer
and the Indenture Trustee, and the due authorization of the Notes for each
series by all necessary action on the part of the applicable Issuer, when the
Notes for each series have been validly executed, authenticated and issued in
accordance with the applicable Indenture and delivered against payment therefor,
the Notes for each series will be valid and binding obligations of the
applicable Issuer, enforceable against the applicable Issuer in accordance with
their terms, subject to bankruptcy, insolvency, reorganization, moratorium or
other similar laws relating to or affecting creditors' rights generally
(including, without limitation, fraudulent conveyance laws), and general
principles of equity, including without limitation, concepts of materiality,
reasonableness, good faith and fair dealing and the possible unavailability of
specific performance or injunctive relief, regardless of whether such
enforceability is considered in a proceeding in equity or at law.

               The opinions expressed above are limited to the federal laws of
the United States of America and the laws of the States of California and New
York (excluding choice of law principles therein). We express no opinion herein
as to the laws of any other jurisdiction and no opinion regarding the statutes,
administrative decisions, rules, regulations or requirements of any county,
municipality, subdivision or local authority of any jurisdiction.

               We consent to the filing of this letter as an exhibit to the
Registration Statement and to the reference to this firm under the heading
"Legal Opinions" in the Prospectus and the Prospectus Supplement, without
admitting that we are "experts," within the meaning of the 1933 Act or the rules
or regulations of the Securities and Exchange Commission thereunder, with
respect to any part of the Registration Statement, including this exhibit.


                                        Respectfully submitted,

                                        /s/  O'MELVENY & MYERS LLP