X0202 4 2005-12-16 0 0001333513 DealerTrack Holdings, Inc. TRAK 0001342016 ONeil Mark F C/O DEALERTRACK HOLDINGS, INC. 1111 MARCUS AVENUE, SUITE M04 LAKE SUCCESS NY 11042 1 1 0 0 Chairman of Board, Pres. & CEO Common Stock 2005-12-16 4 C 0 34121 A 139121 D Common Stock 2005-12-16 4 C 0 1164 A 151164 I By Spouse, as a limited partner of GRP II Partners, L.P. Convertible Series C-2 Preferred Stock 2005-12-16 4 C 0 33921 D Common Stock 34121 0 D Convertible Series C-1 Preferred Stock 2005-12-16 4 C 0 1103 D Common Stock 1164 0 I By Spouse, as a limited partner of GRP II Partners, L.P. Shares of Convertible Series C-2 Preferred Stock were automatically converted into shares of common stock on a 1-to-1.0059 basis upon the closing of the Issuer's initial public offering on December 16, 2005. Includes 30,000 shares of restricted common stock held directly by Mr. O'Neil, and excludes a total of 151,164 shares of common stock held indirectly by Mr. O'Neil, as initially disclosed on Mr. O'Neil's Form 3. Shares of Convertible Series C-1 Preferred Stock were automatically converted into shares of common stock on a 1-to-1.0555 basis upon the closing of the Issuer's initial public offering on December 16, 2005. Includes 100,000 shares of common stock held indirectly by Mr. O'Neil as Trustee for the Mark F. O'Neil Qualified Grantor Retained Annuity Trust, and 50,000 shares of common stock held indirectly by Mr. O'Neil, which shares are held directly by Mr. O'Neil's spouse, as initially disclosed on Mr. O'Neil's Form 3. The shares are held by GRP II Partners, L.P. Monique O'Neil, the spouse of Mark O'Neil, is a limited partner of GRP II Partners, L.P. Through this partnership interest, she has an indirect economic interest in 1,164 shares of common stock. The shares of Convertible Series C-1 Preferred Stock were held by GRP II Partners, L.P. Monique O'Neil, the spouse of Mark O'Neil, is a limited partner of GRP II Partners, L.P. Through this partnership interest, she had an indirect economic interest in approximately 1,103 shares of Convertible Series C-1 Preferred Stock, which automatically converted into 1,164 shares of common stock upon the closing of the Issuer's initial public offering. /s/ Eric D. Jacobs as attorney-in-fact for Mark F. O'Neil 2005-12-20