Exhibit 32(a)

                            CERTIFICATION PURSUANT TO
                             18 U.S.C. SECTION 1350,
                             AS ADOPTED PURSUANT TO
                  SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

     I, Thomas D. Callahan, Chief Executive Officer of Motors Mechanical
Reinsurance Company, Limited (the "Company"), hereby certify, to the best of my
knowledge, that the Company's annual report on Form 10-K (as amended) for the
period ended December 31, 2003 (the "Report") fully complies with the
requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934
(15 U.S.C. 78m or 78o(d)) and that the information contained in the Report
fairly presents, in all material respects, the financial condition and results
of operations of the Company.

Date:  May 3, 2004
                                           /s/ Thomas D. Callahan
                                          --------------------------------------
                                          Name:        Thomas D. Callahan
                                          Title:       Chief Executive Officer

A signed original of this written statement required by Section 906 has been
provided to Motors Mechanical Reinsurance Company, Limited and will be retained
by Motors Mechanical Reinsurance Company, Limited and furnished to the
Securities and Exchange Commission or its staff upon request.