Document:

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                                                                    EXHIBIT 10.6

                                     WAIVER

                                February 28, 2003

To the Parties on the
Attached Exhibit A

          Re:  AmeriCredit MTN Receivables Trust

          Reference is made to that certain Security Agreement dated as of
December 18, 2000, (the "Security Agreement") among the AmeriCredit MTN
Receivables Trust, as Debtor (the "Debtor"), AmeriCredit Financial Services,
Inc., individually and as servicer (the "Servicer"), AmeriCredit MTN Corp.,
individually, and The Chase Manhattan Bank, as Collateral Agent and as
Securities Intermediary (the "Collateral Agent) and the Servicing and Custodian
Agreement (the "Servicing and Custodian Agreement") dated as of December 18,
2000, by and among the Servicer, the Debtor and the Collateral Agent.
Capitalized terms used herein but not defined herein shall have the meanings
ascribed to such terms in the Security Agreement or the Servicing and Custodian
Agreement, as the case may be.

          Section 6.1(r) of the Security Agreement provides that a Termination
and Amortization Event shall occur if the Cumulative Net Loss Ratio exceeds the
amount specified for the related Determination Date in Exhibit M to the Security
Agreement. MBIA Insurance Corporation ("MBIA") is aware that for the
Determination Date occurring in March 2003, the Cumulative Net Loss Ratio
exceeds the amount specified in Exhibit M to the Security Agreement, therefore a
Termination and Amortization Event pursuant to Section 6.1(r) of the Security
Agreement has occurred (the "March Termination and Amortization Event"). Section
4.1(e) of the Servicing and Custodian Agreement provides that a Servicer
Termination Event shall occur upon the occurrence of a Termination and
Amortization Event listed in Section 6.1 of the Security Agreement. As a result
of the March Termination and Amortization Event, a Servicer Termination Event
has occurred for March 2003 (the "March Servicer Termination Agreement").
Section 5.01 (c) and (h) of the Insurance Agreement provide that an Event of
Default under the Insurance Agreement shall occur upon the occurrence of a
Termination and Amortization Event or a Servicer Termination Event. As a result
of the March Termination and Amortization Event and the March Servicer
Termination Agreement, an Event of Default under the Insurance Agreement has
occurred for March 2003 (the "March Insurance Agreement Event of Default").

<PAGE>

          Pursuant to Section 6.2 of the Security Agreement, Section 4.5 of the
Servicing and Custodian Agreement, and Section 5.03 of the Insurance Agreement,
you are hereby notified that MBIA waives the March Termination and Amortization
Event, the March Servicer Termination Event and the March Insurance Agreement
Event of Default for all purposes under the Transaction Documents.

          Notwithstanding the foregoing or anything to the contrary herein, in
the Security Agreement, the Servicing and Custodian Agreement or the Transaction
Documents or in any other document in connection therewith, MBIA intends this
waiver to be limited to the event described herein and shall not constitute, and
shall not be construed to be, a waiver of any future Termination and
Amortization Event, Servicer Termination Event, the Event of Default under the
Insurance Agreement or any other event. This waiver is wholly without prejudice
to, and, other than as specifically set forth herein, shall not constitute a
waiver in any respect of, the rights of MBIA in respect of its rights under the
Transaction Documents and shall not in any way alter or affect the rights,
duties or obligations of MBIA under the Transaction Documents.

                                                MBIA INSURANCE CORPORATION

                                                By /s/ Rosemary Kelley
                                                   -----------------------------

Signature Page to February 28, 2003
Waiver (MTN)

<PAGE>

                                    EXHIBIT A

AmeriCredit Financial Services Inc.
801 Cherry Street
Suite 3900
Fort Worth, Texas 76102
Telecopy: (817) 302-7942

AmeriCredit MTN Corp.
801 Cherry Street
Suite 4000
Fort Worth, Texas 76102
Attention: Treasury Department
Telecopy: (817) 302-7082

AmeriCredit MTN Receivables Trust
C/o Deutsche Bank Trust Company Delaware,
formerly known as Bankers Trust (Delaware)
E.A. Delle Donne Corporate Center
Montgomery Building
1011 Centre Road, Suite 200
Wilmington, DE 19805
Telecopy: (302) 636-3222

JPMorgan Chase Bank, formerly
known as The Chase Manhattan Bank
450 West 33rd Street, 14th Floor
New York, NY 10001
Attention: AmeriCredit MTN Receivables Trust
Telecopy: (212) 946-8302

                                        3<PAGE>

                                                                    EXHIBIT 10.7

                                                                  EXECUTION COPY

                                 AMENDMENT NO. 3

                          dated as of February 28, 2003

                                      among

                       AMERICREDIT MTN RECEIVABLES TRUST,

                                   as Debtor,

                      AMERICREDIT FINANCIAL SERVICES, INC.,

                          Individually and as Servicer,

                           MBIA INSURANCE CORPORATION,

                                   as Insurer

                                       and

                         MERIDIAN FUNDING COMPANY, LLC,

                                  as Purchaser

                              to SECURITY AGREEMENT

                          dated as of December 18, 2000

<PAGE>

          AMENDMENT NO. 3, dated as of February 28, 2003 (the "Amendment"),
among AMERICREDIT MTN RECEIVABLES TRUST (the "Debtor"), AMERICREDIT FINANCIAL
SERVICES, INC., individually and in its capacity as Servicer ("AFS"), MBIA
INSURANCE CORPORATION, as Insurer ("MBIA"), and MERIDIAN FUNDING COMPANY, LLC,
as Purchaser ("Meridian"), to the Security Agreement dated as of December 18,
2000 (the "Security Agreement"), among the Debtor, AFS, AmeriCredit MTN Corp.
and the Chase Manhattan Bank (predecessor to JPMorgan Chase Bank), as Collateral
Agent and Securities intermediary.

          WHEREAS, Section 9.2(b) of the Security Agreement permits amendment of
the Security Agreement by the Debtor, AFS, MBIA and Meridian (the "Parties")
upon the terms and conditions specified therein;

          WHEREAS, the Security Agreement has previously been amended by
Amendment No. 1, dated as of December 1, 2002, and Amendment No. 2, dated as of
February 1, 2003, among the Parties;

          WHEREAS, the Parties wish to amend the Security Agreement.

          NOW, THEREFORE, the Parties agree that the Security Agreement is
hereby amended effective as of the date hereof as follows:

          Section 1. Definitions. Each term used herein but not defined herein
shall have the meaning assigned to such term in the Security Agreement.

          Section 2. Amendment to Section 1.1 (Certain Defined Terms)

          (a) The definition of "Amortization Period Reserve Percentage" in
Section 1,1 is deleted in its entirety and replaced with the following:

          "Amortization Period Reserve Percentage" means,

               (x)  with respect to any date of determination which occurs after
                    the commencement of the Amortization Period and prior to the
                    seventh (7th) Remittance Date during the Amortization
                    Period:

                    (i)   13.0% if the Portfolio Net Loss Ratio calculated as of
                          the most recent Determination Date is less than 7.00%.

                    (ii)  14.0%, if the Portfolio Net Loss Ratio calculated as
                          of the most recent Determination Date is greater than
                          or equal to 7.00% but less than 7.50%.

                    (iii) 15.0%, if the Portfolio Net Loss Ratio calculated as
                          of the most recent Determination Date is greater than
                          or equal to 7.50% but less than 8.00%.

                                        2

<PAGE>

                    (iv)  16.0%, if the Portfolio Net Loss Ratio calculated as
                          of the most recent Determination Date is greater than
                          or equal to 8.00% but less than 8.50%.

                    (v)   17.0%, if the Portfolio Net Loss Ratio calculated as
                          of the most recent Determination Date is greater than
                          or equal to 8.50%; and

               (y)  with respect to any date of determination occurring on and
                    after the seventh (7th) Remittance Date during the
                    Amortization Period, the applicable percentage set forth in
                    the numbered clauses (i) through (v) in paragraph (x) above
                    calculated with respect to the (6th) Remittance Date.

          (b) The definition of "Initial Reserve Percentage" in Section 1.1 is
deleted in its entirety and replaced with the following:

          "Initial Reserve Percentage" means, with respect to any Delivery Date:

               (i) 6%, if both

                    (a) the Weighted Average AmeriCredit Score of all Eligible
                    Receivables (including the Receivables to be delivered on
                    such Receivables Delivery Date) is greater than or equal to
                    227.00; and

                    (b) the most-recently calculated Portfolio Net Loss Ratio is
                    less than 7.00%

               (ii) 7%, if either

                    (a) the Weighted Average AmeriCredit Score of all Eligible
                    Receivables (including the Receivables to be delivered on
                    such Receivables Delivery Date) is greater than or equal to
                    226.00 but less than 227.00; or

                    (b) the most-recently calculated Portfolio Net Loss Ratio is
                    greater than or equal to 7.00% but less than 7.50%.

               (iii) 8%, if either

                    (a) the Weighted Average AmeriCredit Score of all Eligible
                    Receivables (including the Receivables to be delivered on
                    such Receivables Delivery Date) is less than 226.00; or

                    (b) the most-recently calculated Portfolio Net Loss Ratio is
                    greater than or equal to 7.50% but less than 8.00%.

               (iv) 9%, if

                                        3

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                    (a) the most-recently calculated Portfolio Net Loss Ratio is
                    greater than or equal to 8.00%.

          (c) The definition of "Net Spread Deficiency" in Section 1.1 is
deleted in its entirety and replaced with the following:

          "Net Spread Deficiency" means, as of any Borrowing Base Determination
          Date, the positive difference, if any, of (i) the sum of (A) 8.75%
          plus (B) the Servicing Fee, expressed as a percentage of the Net
          Receivables Balance plus (C) the lesser of (x) one-month LIBOR plus
          (I) from the Closing Date up to and including the thirty-sixth (36th)
          Remittance Date, 0.7205% and (II) after the thirty-sixth (36th)
          Remittance Date, 1.8505% and (y) the weighted average strike price
          under the Hedging Arrangements then in effect, minus (ii) the weighted
          average APR of all Eligible Receivables then held as Collateral.

          (d) The definition of "Reserve Account Required Amount" in Section 1.1
is deleted in its entirety and replaced with the following:

          "Reserve Account Required Amount" means,

                    (x) as of any Borrowing Base Determination Date during the
                    Revolving Period, the product of (i) the applicable
                    Revolving Period Reserve Percentage and (ii) the Net
                    Receivables Balance as of such Borrowing Base Determination
                    Date; and

                    (y) as of any date of determination during the Amortization
                    Period, the lesser of:

                         (i)  the greatest of:

                              (A) 6.0% of the Aggregate Outstanding Balance of
                              all Receivables as of the commencement of the
                              Amortization Period;

                              (B) the product of (I) the applicable Amortization
                              Period Reserve Percentage and (II) the Aggregate
                              Outstanding Balance of all Receivables as of such
                              date of determination; and

                              (C) the product of (I) the Credit Score Based
                              Reserve Percentage applicable to the Amortization
                              Period and (II) the Aggregate Outstanding Balance
                              of all Receivables as of such date of
                              determination; and

                         (ii) the Net Investment as of such date of
                              determination

                                        4

<PAGE>

          (e) The definition of "Revolving Period Reserve Percentage" in Section
1.1 is deleted in its entirety and replace with the following:

          "Revolving Period Reserve Percentage" means, with respect to any
          Borrowing Base Determination Date during the Revolving Period, the sum
          of (x) if, and only if, the Weighted Average Age of the Eligible
          Receivables then exceeds 180.00 days, 3%, plus (y) the applicable
          percentage set forth in the numbered clauses (i) through (v) below:

               (i) 8%, if both

                    (a) the Weighted Average AmeriCredit Score of all Eligible
                    Receivables as of such date of determination, after taking
                    into account all Facility Activity on such date is greater
                    than or equal to 227.00; and

                    (b) the most-recently calculated Portfolio Net Loss Ratio is
                    less than 7.00%.

               (ii) 9%, if either

                    (a) the Weighted Average AmeriCredit Score of all Eligible
                    Receivables as of such date of determination, after taking
                    into account all Facility Activity on such date is greater
                    than or equal to 226.00 but less than 227.00; or

                    (b) the most-recently calculated Portfolio Net Loss Ratio is
                    greater than or equal to 7.00% but less than 7.50%.

               (iii) 10%, if either

                    (a) the Weighted Average AmeriCredit Score of all Eligible
                    Receivables as of such date of determination, after taking
                    into account all Facility Activity on such date is greater
                    than or equal to 224.00 but less than 226.00; or

                    (b) the most-recently calculated Portfolio Net Loss Ratio is
                    greater than or equal to 7.50% but less than 8.00%.

               (iv) 11%, if either

                    (a) the Weighted Average AmeriCredit Score of all Eligible
                    Receivables as of such date of determination, after taking
                    into account all Facility Activity on such date is less than
                    224.00; or

                    (b) the most-recently calculated Portfolio Net Loss Ratio is
                    greater than or equal to 8.00%.

          (f) A new definition of "GAAP Portfolio Net Loss Ratio" is added to
Section 1.1 in alphabetical order as follows:

                                        5

<PAGE>

"GAAP Portfolio Net Loss Ratio" means, as of any date of determination, the
ratio (expressed as a percentage), computed by dividing "A" by "B", and then
multiplying the result by "C" where:

               "A" is equal to the net charge-offs (as defined in AmeriCredit
               Corp.'s 10-Q and 10-K SEC filings) for the Servicing Portfolio
               that have occurred during the six Settlement Periods immediately
               preceding such date divided by (ii) the average Aggregate
               Outstanding Balance of the Servicing Portfolio during such
               six-month period;

               "B" is equal to the actual number of days in such six-month
               period; and

               "C" is equal to the actual number of days in the Servicer's
               fiscal year in which the most recently ended Settlement Period
               occurred.

Section 3. Amendment to Section 6.1 (Termination and Amortization Events).

(a) Clause (p) of Section 6.1 is deleted in its entirety and replaced with the
following:

          (p)  the Portfolio Net Loss Ratio (i) for any Determination Date
          occurring prior to March 1, 2003 shall exceed 8.00%, (ii) for any
          Determination Date occurring subsequent to March 1, 2003 and prior to
          August 1, 2003 shall exceed 9.00%, or (iii) for any Determination Date
          occurring subsequent to August 1, 2003 shall exceed 8.00%; or

(b) Clause (q) of Section 6.1 is deleted in its entirety and replaced with the
following:

          (q)  the Portfolio Repossession Ratio, on a 3-month rolling average
          basis, (i) as measured on or prior to the February 2003 Determination
          Date, is greater than 1.5%, (ii) as measured on the Determination
          Dates occurring in the months March 2003 through July 2003 is greater
          than 2.00%, or (iii) as measured on or subsequent to the August 2003
          Determination Date is greater than 1.5%; or

(c) Clause (z) of Section 6.1 is deleted in its entirety and replaced with the
following:

          (z)  the ratio of AmeriCredit Corp.'s EBITDA (plus any loss provision
          minus net charge-offs and excluding in the calculation a one-time,
          non-cash impairment charge to the credit enhancement assets related to
          the present value effect of the expected delay in receiving cash
          distributions from FSA insured securitization trusts) for the
          financial quarter ended December 31, 2002 to its Interest Expense for
          the financial quarter ended December 31, 2002 shall be less than 1.5x.
          The ratio of AmeriCredit Corp.'s EBITDA (plus any charge or charges
          related to restructuring, plus any loss provision minus net
          charge-offs) for the financial quarter ended March 31, 2003 to its
          Interest Expense for the financial quarter ended

                                        6

<PAGE>

          March 31, 2003 shall be less than 1.8x. The average of the ratios of
          AmeriCredit Corp.'s EBITDA to Interest Expense for the two most recent
          financial quarters ended June 30, 2003 shall be less than l.0x. The
          average of the ratios of AmeriCredit Corp.'s EBITDA to Interest
          Expense for the two most recent financial quarters ended September 30,
          2003 or December 31, 2003 shall be less than 1.1x. The average of the
          ratios of AmeriCredit Corp.'s EBITDA to Interest Expense for the two
          most recent financial quarters ended March 31, 2004 and any two
          consecutive financial quarters thereafter shall be less than 1.2x; or

(d) Clause (11) of Section 6.1 is deleted in its entirety and replaced with the
following:

          (11) a Servicer Termination Event occurs; or

(e) A new Section 6.1(mm) is added as follows:

          (mm) the GAAP Portfolio Net Loss Ratio for any Determination Date
          exceeds 8.00%; or

(f) A new Section 6.1(nn) is added as follows:

          (nn) Excluding MBIA's MTN transactions, AmeriCredit fails to maintain
          $1.75 billion in committed and in good standing warehouse facilities.

                   [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK
                             SIGNATURE PAGE FOLLOWS]

                                        7

<PAGE>

          IN WITNESS WHEREOF, the parties hereto have executed this Amendment as
of the date set forth on the first page hereof.

                                        AMERICREDIT MTN RECEIVABLES TRUST

                                        By: DEUTSCHE BANK TRUST COMPANY
                                            DELAWARE, not in its individual
                                            capacity but solely as Owner
                                            Trustee on behalf of the Issuer

                                                                ATTORNEY-IN-FACT

                                        By: /s/ Louis Bodi
                                            ------------------------------------
                                           Name:  LOUIS BODI
                                           Title: VICE PRESIDENT

                                        AMERICREDIT FINANCIAL SERVICES, INC.,
                                         Individually and as Servicer,

                                        By: /s/ Beth Sorensen
                                            ------------------------------------
                                           Name:  Beth Sorensen
                                           Title: Senior Vice President, Finance

                                        MBIA INSURANCE CORPORATION,
                                         as Insurer,

                                        By  /s/ Rosemary Kelley
                                            ------------------------------------
                                           Name:  Rosemary Kelley
                                           Title: Director

                                        MERIDIAN FUNDING COMPANY, LLC,
                                         as Purchaser

                                        By  /s/ Bernard J. Angelo
                                            ------------------------------------
                                           Name:  Bernard J. Angelo
                                           Title: Vice President

Signature Page for Amendment No. 3
to the Security Agreement (MTN)

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