UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                  SCHEDULE 13G

                    Under the Securities Exchange Act of 1934

                            (Amendment No.     4    )*
                                           ---------

                            GP Strategies Corporation
--------------------------------------------------------------------------------
                                (Name of Issuer)

                                  Common Stock
--------------------------------------------------------------------------------
                         (Title of Class of Securities)

                                    36225V104
                            -----------------------
                                 (CUSIP Number)

                                December 31, 2003
         --------------------------------------------------------------
             (Date of Event Which Requires Filing of this Statement)


            Check the appropriate box to designate the rule pursuant
                        to which this Schedule is filed:

                                [x] Rule 13d-1(b)
                                [_] Rule 13d-1(c)
                                [_] Rule 13d-1(d)

*The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities, and
for any subsequent amendment containing information which would alter the
disclosures provided in a prior cover page.

The information required in the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the Securities Exchange Act of
1934 ("Act") or otherwise subject to the liabilities of that section of the Act
but shall be subject to all other provisions of the Act (however, see the
Notes).

                                Page 1 of 9 Pages



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CUSIP No.  36225V104                  13G                  Page 2 of 9 Pages
          ------------
-----------------------                                 ------------------------

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1    NAME OF REPORTING PERSON
     S.S. or I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

        Columbia Wanger Asset Management, L.P.  36-3820584
--------------------------------------------------------------------------------

2    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*

        Not Applicable                                                (a) [_]
                                                                      (b) [_]
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3    SEC USE ONLY

--------------------------------------------------------------------------------
4    CITIZENSHIP OR PLACE OF ORGANIZATION

        Delaware
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    NUMBER OF    5   SOLE VOTING POWER

     SHARES              None
                 ---------------------------------------------------------------
  BENEFICIALLY   6   SHARED VOTING POWER

   OWNED BY              870,000
                 ---------------------------------------------------------------
    EACH         7   SOLE DISPOSITIVE POWER

   REPORTING             None
                 ---------------------------------------------------------------
  PERSON WITH    8   SHARED DISPOSITIVE POWER

                         870,000
--------------------------------------------------------------------------------
9    AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

        870,000
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10   CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

        Not Applicable                                                    [_]
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11   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

        5.3 %
--------------------------------------------------------------------------------
12   TYPE OF REPORTING PERSON*

        IA
--------------------------------------------------------------------------------



-----------------------                                 ------------------------
CUSIP No.  36225V104                  13G                  Page 3 of 9 Pages
          ------------
-----------------------                                 ------------------------

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1    NAME OF REPORTING PERSON
     S.S. or I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

        WAM Acquisition GP, Inc.
--------------------------------------------------------------------------------

2    CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*

        Not Applicable                                                (a) [_]
                                                                      (b) [_]
--------------------------------------------------------------------------------
3    SEC USE ONLY

--------------------------------------------------------------------------------
4    CITIZENSHIP OR PLACE OF ORGANIZATION

        Delaware
--------------------------------------------------------------------------------
    NUMBER OF    5   SOLE VOTING POWER

     SHARES              None
                 ---------------------------------------------------------------
  BENEFICIALLY   6   SHARED VOTING POWER

   OWNED BY              870,000
                 ---------------------------------------------------------------
    EACH         7   SOLE DISPOSITIVE POWER

  REPORTING              None
                 ---------------------------------------------------------------
  PERSON WITH    8   SHARED DISPOSITIVE POWER

                         870,000
--------------------------------------------------------------------------------
9    AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

        870,000
--------------------------------------------------------------------------------
10   CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

        Not Applicable                                                    [_]
--------------------------------------------------------------------------------
11   PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9

        5.3 %
--------------------------------------------------------------------------------
12   TYPE OF REPORTING PERSON*

        CO
--------------------------------------------------------------------------------



Item 1(a)      Name of Issuer:

                   GP Strategies Corporation

Item 1(b)      Address of Issuer's Principal Executive Offices:

                   777 Westchester Avenue
                   White Plains, NY 10604

Item 2(a)      Name of Person Filing:

                   Columbia Wanger Asset Management, L.P. ("WAM")
                   WAM Acquisition GP, Inc., the general partner of WAM
                     ("WAM GP")

Item 2(b)      Address of Principal Business Office:

                   WAM and WAM GP are both located at:

                   227 West Monroe Street, Suite 3000
                   Chicago, Illinois  60606

Item 2(c)      Citizenship:

                   WAM is a Delaware limited partnership and WAM GP is a
                   Delaware corporation.

Item 2(d)      Title of Class of Securities:

                   Common Stock

Item 2(e)      CUSIP Number:

                   36225V104

Item 3         Type of Person:

                   (e)  WAM is an Investment Adviser registered under section
                        203 of the Investment Advisers Act of 1940; WAM GP is
                        the General Partner of the Investment Adviser.

                               Page 4 of 9 Pages



Item 4      Ownership (at December 31, 2003):

                 (a)   Amount owned "beneficially" within the meaning of
                       rule 13d-3:

                       870,000

                 (b)   Percent of class:

                       5.3 % (based on 16,288,493 shares outstanding as of
                       November 7, 2003).

                 (c)   Number of shares as to which such person has:

                           (i)    sole power to vote or to direct the vote: none

                           (ii)   shared power to vote or to direct the
                                  vote: 870,000

                           (iii)  sole power to dispose or to direct the
                                  disposition of: none

                           (iv)   shared power to dispose or to direct
                                  disposition of: 870,000

Item 5      Ownership of Five Percent or Less of a Class:

                 Not Applicable

Item 6      Ownership of More than Five Percent on Behalf of Another Person:

                 The shares reported herein have been acquired on behalf of
                 discretionary clients of WAM. Persons other than WAM and WAM GP
                 are entitled to receive all dividends from, and proceeds from
                 the sale of, those shares.

Item 7      Identification and Classification of the Subsidiary Which Acquired
            the Security Being Reported on by the Parent Holding Company:

                 Not Applicable

Item 8      Identification and Classification of Members of the Group:

                 Not Applicable

Item 9      Notice of Dissolution of Group:

                 Not Applicable

                               Page 5 of 9 Pages



Item 10     Certification:

                    By signing below I certify that, to the best of my knowledge
                 and belief, the securities referred to above were acquired and
                 are held in the ordinary course of business and were not
                 acquired and are not held for the purpose of or with the effect
                 of changing or influencing the control of the issuer of the
                 securities and were not acquired and are not held in connection
                 with or as a participant in any transaction having that purpose
                 or effect.

                               Page 6 of 9 Pages



                                    Signature

     After reasonable inquiry and to the best of my knowledge and belief, I
certify that the information set forth in this statement is true, complete and
correct.

Date: February 10, 2004

               The undersigned corporation, on the date above written, agrees
               and consents to the joint filing on its behalf of this Schedule
               13G in connection with its beneficial ownership of the security
               reported herein.

                                     WAM Acquisition GP, Inc.
                                       for itself and as general partner of
                                       COLUMBIA WANGER ASSET
                                       MANAGEMENT, L.P.

                                     By: /s/ Bruce H. Lauer
                                         ---------------------------------------
                                             Bruce H. Lauer
                                             Senior Vice President and Secretary

                               Page 7 of 9 Pages



                                  Exhibit Index

Exhibit 1    Joint Filing Agreement dated as of February 10, 2004 by and between
             Columbia Wanger Asset Management, L.P. and WAM Acquisition GP, Inc.

                               Page 8 of 9 Pages



                                                                       EXHIBIT 1

                             JOINT FILING AGREEMENT

     The undersigned hereby agree to the joint filing of the Schedule 13G to
which this Agreement is attached.

        Dated:  February 10, 2004

                                     WAM Acquisition GP, Inc.
                                       for itself and as general partner of
                                       COLUMBIA WANGER ASSET MANAGEMENT, L.P.

                                     By: /s/ Bruce H. Lauer
                                         ---------------------------------------
                                             Bruce H. Lauer
                                             Senior Vice President and Secretary

                               Page 9 of 9 Pages