Speed Racer was fun (even though a lot of people I've spoken to don't seem to like it). Never really watched the cartoon so can't compare it, but I enjoyed the movie for what it was.
Dirty Mary Crazy Larry has been added to the list. Another Peter Fonda flick I guess could be considered a car movie, even though it's a R.V., is Race with the Devil. Some interesting chase scenes in that one.
American Graffiti is a classic. I think I actually enjoyed the documentary on the making of the movie as much as I did the movie itself.