I had my white car maxed out back in the day, I have no idea how fast it was, I want to say like 130-135 maybe in a basically stock car with 4.10s. I had my little SRT4 maxed out back in the day, which was like 145-150ish, I know it went faster than the white car did and felt better than the GT did, FBO car. Fastest I've taken a car so far was the procharged C5 I had, it was up around the 170 mark and still had steam left but I don't think it would have crested 200mph and that was a car with 700whp. It might have but it felt too good at speed which is half the reason I shipped it down the road.
Big empty flat highways and being a dumbass can be fun.