X0202 4 2007-07-11 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 2007-07-11 4 M 0 20000 3.12 A 322280 D Common Stock 2007-07-11 4 S 0 100 38.13 D 322180 D Common Stock 2007-07-11 4 S 0 100 38.14 D 322080 D Common Stock 2007-07-11 4 S 0 100 38.15 D 321980 D Common Stock 2007-07-11 4 S 0 468 38.16 D 321512 D Common Stock 2007-07-11 4 S 0 200 38.17 D 321312 D Common Stock 2007-07-11 4 S 0 500 38.18 D 320812 D Common Stock 2007-07-11 4 S 0 400 38.19 D 320412 D Common Stock 2007-07-11 4 S 0 732 38.20 D 319680 D Common Stock 2007-07-11 4 S 0 200 38.21 D 319480 D Common Stock 2007-07-11 4 S 0 100 38.22 D 319390 D Common Stock 2007-07-11 4 S 0 324 38.23 D 319056 D Common Stock 2007-07-11 4 S 0 700 38.24 D 318356 D Common Stock 2007-07-11 4 S 0 535 38.25 D 317821 D Common Stock 2007-07-11 4 S 0 265 38.26 D 317556 D Common Stock 2007-07-11 4 S 0 400 38.27 D 317156 D Common Stock 2007-07-11 4 S 0 600 38.28 D 316556 D Common Stock 2007-07-11 4 S 0 400 38.29 D 316156 D Common Stock 2007-07-11 4 S 0 500 38.30 D 315656 D Common Stock 2007-07-11 4 S 0 200 38.31 D 315456 D Common Stock 2007-07-11 4 S 0 500 38.32 D 314956 D Common Stock 2007-07-11 4 S 0 100 38.33 D 314856 D Common Stock 2007-07-11 4 S 0 100 38.34 D 314756 D Common Stock 2007-07-11 4 S 0 400 38.35 D 314356 D Common Stock 2007-07-11 4 S 0 476 38.36 D 313880 D Common Stock 2007-07-11 4 S 0 800 38.37 D 313080 D Common Stock 2007-07-11 4 S 0 100 38.38 D 312980 D Common Stock 2007-07-11 4 S 0 200 38.39 D 312780 D Common Stock 50583 I By Spouse Common Stock 90686 I as Trustee for The Mark F. O'Neil Qualified Grantor Retained Annuity Trust Non-Qualified Stock Option (right to buy) 3.12 2007-07-11 4 M 0 20000 0.00 D 2006-01-16 2016-01-16 Common Stock 20000 164941 D Includes 251,250 shares of restricted common stock. The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on October 10, 2006 and amended on May 21, 2007. Due to the SEC's row number limitations this Form 4 is being filed in three parts. This is part 1 of 3 /s/ Eric D. Jacobs as attorney-in-fact for Mark F. O'Neil 2007-07-12