Nothing wrong with RAP music, sounds anti-rap to me. I've been a DJ since I was 16 (33 now) and while there alot I don't listen to on a regular basis, that is my choice, I have an open mind about music in general.
IMHO -
House and rock tend to work best with anything automotive related. Its really difficut to find the right RAP song to use and I really haven't found one yet.
"Act A Fool" by Ludacris since it's from 2 Fast 2 Furious would make since.
Other picks would be -
"One More Try" by Daft Punk
The way the song is made with it's breaks, would make great use of creative editing.
"I can drive 55" - by Sammy Hargar would work very well for obivous reasons.
Just keep an open mind about your selection, some are very natural to use...