It's only $20, go buy it now! Great graphics, tons of cars with lots of crap you can do, kinda fuzzy physics but their still fun. I haven't put it down in the two weeks I've had it.
This game is basically NFS underground, but with more cars, more options, the chance to tune your cars to how you like it, and just plain more fun in my opinion. BTW, there are Mazdas, my first car was a miata, now im in an rx8.