EXHIBIT 99.1




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

In connection with the Annual Report of General Motors Corporation (the
"Corporation") on Form 11-K for the period ending December 31, 2002 as filed
with the Securities and Exchange Commission on the date hereof (the "Report"),
I, David C. Walker, Chief Financial Officer of the GMAC Mortgage Group, Inc., in
reference to the GMAC Mortgage Group, Inc. Savings Incentive Plan, certify,
pursuant to 18 U.S.C. ss. 1350, as adopted pursuant to ss. 906 of the
Sarbanes-Oxley Act of 2002, that to the best of my knowledge:

(1) The Report fully complies with the requirements of section 13(a) or 15(d) of
the Securities Exchange Act of 1934; and

(2) The information contained in the Report fairly presents, in all material
respects, the financial condition and results of operations of the Plan.


/s/ DAVID C. WALKER.
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David C. Walker.
Chief Financial Officer,
GMAC Mortgage Group, Inc.
June 27, 2003