I found that its easier to advance by buying cars on the Xbox Live auction house that will put you ahead of everyone else. This weekend, I got to a point where I can hardly drive the cars.
I won the 2002 Lingenfelter Z06 700+ hp Corvette. I modded the crap out of it, and lightened it, and I can’t control it. It seriously is the most squirmy car I have ever driven in this game. It actually is almost annoying. I will be in 3rd gear, and give it half throttle, and the backend will just kick out from behind, even on race slicks.
I ran it into the wall several times.
Check this out:
(Click for high-res)
This week, I am going to try and learn how to drive this basterd!