We were just playing this on Xbox... I got tired of my Focus with all it's level 2 stuff and got an A3, which was faster than my Focus with just stock stuff. I got it to 6 stars in no time after getting a bunch of unique parts. Finally got some level 3 upgrades and a unique ECM (don't think it helps much, but oh well). I can hit around 200ish in the A3 with boost.
My friend's Skyline maxes out at 217 (like some sort of rev limiter at around 10,000RPM).
Apparantly the Audi TT can have the fastest 0-100 time of less than 7 seconds... beats the Skyline by a few tenths. Found a list on some gaming site.
Also he has beaten it, but is only 60 something percent done. I guess you have to do all the SUV races during each level (sponsor) or you can't go back and do them again. Oops.