AFFINIA GROUP HOLDINGS INC.

EXHIBIT 10.12

AFFINIA GROUP HOLDINGS INC.

0000 Xxxxxx Xxxx Xxxxxx

Xxxxxx, Xxxx 00000

January 24, 2005

To the Stockholders identified on the signature pages hereto:

Reference is hereby made to the Stockholder s Agreement dated as of November 30, 2004 (the “Agreement”) among Affinia Group Holdings Inc. (“Parent”), Cypress Merchant Banking Partners II LP. (“Cypress Onshore”), Cypress Merchant Banking II C.V. (“Cypress Offshore”), 55™ Street Partner s II L.P, (“55th Street”), Cypress Side-by-Side LLC (“Side-by-Side” and, together with Cypress Onshore, Cypress Offshore and 55th Street, the “Cypress Group”), Ontario Municipal Employees Retirement Board (“OMERS”), The Northwestern Mutual Life Insurance Company f “NW Mutual”). California State Teachers’ Retirement System (“CalSTRS”), and Xxxxxxxxx Fund, L.P. (“Xxxxxxxxx” and, together with the Cypress Group, OMERS, NW Mutual and CalSTRS, the “Stockholders”). All capitalized terms used in this letter agreement (but not defined in this letter agreement) shall have the meanings assigned such terms in the Agreement.

Pursuant to Section 4.5 of the Agreement, (i) each committee of the Boar d of Director s must consist of at least three members, with Cypress Director s constituting a majority of each committee and one Independent Director selected by the Boar d of Director s serving on each committee and (ii) the Nominating Committee must consist of one Cypress Director, one Investors’ Director and one Independent Director (unless there is no Investors’ Director at any time, in which case the Nominating Committee must consist of one Cypress Director and two Independent Director s) .

Parent and the Stockholders hereby agree as follows:

(i) for purposes of Section 4.5 of the Agreement, all references to “Independent Director” or “Independent Directors” shall mean “director who is Independent” or “directors who are Independent”; and

(ii) with the consent of any Cypress Member, the number of Cypress Director s serving from time to time on any committee of the Board of Directors may constitute less than a majority, provided that the Cypress Members shall have the right, exercisable at any time, to remove any director from a committee (other than the Nominating Committee) and replace such director with a Cypress Director to ensure that Cypress Directors constitute a majority of such committee (so long as at least one director who is Independent remains on such committee in accordance with Section 4.5(a)).

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IN WITNESS WHEREOF, the parties hereto have signed and delivered this letter agreement as of the date first above written.

AFFINIA GROUP HOLDINGS INC.
By:		/s/ Xxxxxx X. Xxxxxx
		Name: Xxxxxx X. Xxxxxx
		Title: Senior Vice President and Chief Financial Officer
CYPRESS MERCHANT BANKING PARTNERS II L.P.
By:		Cypress Associates II LLC, its general partner
By:		/s/ Xxxxx X. Xxxxxxxx
		Name: Xxxxx Xxxxxxxx
		Title: Managing Member
55TH STREET PARTNERS II L.P.
By:		Cypress Associates II LLC, its general partner
By:		/s/ Xxxxx X. Xxxxxxxx
		Name: Xxxxx Xxxxxxxx
		Title: Managing Member
CYPRESS MERCHANT BANKING II C.V.
By:		Cypress Associates II LLC, its general partner
By:		/s/ Xxxxx X. Xxxxxxxx
		Name: Xxxxx Xxxxxxxx
		Title: Managing Member
CYPRESS SIDE-BY-SIDE L.L.C.
By:		/s/ Xxxxx X. Xxxxxxxx
		Name: Xxxxx Xxxxxxxx
		Title: Authorized Signer

Signature Page - Letter Agreement

ONTARIO MUNICIPAL EMPLOYEES RETIREMENT BOARD
By:		/s/ Xxxx Xxxxx
		Name: Xxxx Xxxxx
		Title: Senior Vice President
By:		/s/ Xxx Xxxxxxx
		Name: Xxx Xxxxxxx
		Title: CEO, OMERS Capital Partners

Signature Page - Letter Agreement

THE NORTHWESTERN MUTUAL LIFE INSURANCE COMPANY
By:		/s/ Xxxx X. Xxxxxxx
		Name: Xxxx X. Xxxxxxx
		Title: Its Authorized Representative

Signature Page - Letter Agreement

CALIFORNIA STATE TEACHERS’ RETIREMENT SYSTEM
By:		/s/ Xxxxxxx X. Xxxx
		Name: Xxxxxxx X. Xxxx
		Title: Principal Investment Officer

Signature Page - Letter Agreement

XXXXXXXXX FUND, L.P.
By:		Xxxxxxxxx Managers, LLC, its general partner
By:		/s/ Xxxxxxx Xxxxxx
		Name: Xxxxxxx Xxxxxx
		Title: Vice President

Signature Page - Letter Agreement