Car Game question

I am looking for a racing game where you race obviously but are able to modify your cars as you win more. I think it was Midnight club or need for speed that i used to play where you could do this, but that was many years ago. What are the more recent and better rated games that you can do this in?

I would wait a bit a get Forza Motorsport 3, it is supposed to be gret racing, and customizing cars.