Rob Dougan's stuff is really good:
Speed Me Towards Death, Chateau (really hectic), Furious Angels - if you don't dig his voice, stick with the instrumentals.
Chemical Brothers (as Hammond mentioned):
Where Do I Begin? (when it kicks in), The Boxer (after the vocal melody climaxes at 3:24), Get Yourself High (when the bassline kicks in at 3:42), Hold Tight London (speeding through a cityscape late at night).
also try:
Ghettomusick (Benny Bennassi remix) - Outkast (good doof doof stuff).
Ghostwriter - RJD2 (for some cruisin')
Moonlight and Mescaline - Kinobe (Fear and Loathing style desert cruise at night)
Hypermusic - Muse (insane rock music for insane speeds)
Wylin' Out - Mos Def, RJD2, Diverse and Prefuse 73 (on second thoughts, maybe not, but I enjoy myself when I drive to it)
Lucky Star (feat Dizee Rascal) - Basement Jaxx
Gangster Trippin' - Fatboy Slim
Slash Dot Slash - Fatboy Slim (annoying song, but hectic enough for a speed session)
Ya Mama - Fatboy Slim
oh, and how could I forget an all-time favourite:
The Immigrant Song - Led Zepellin