Save your money.
In the previous game, as unrealistic as it may have been, was fairly fun. Lot's of drifting courses and the 'all too awesome mad tyte yo' 240 and silvia cars made it all the more fun. Unfortunately for pro street, drifting was ignored. It screams horror. The actual drifting in the game is nowhere near the way it's portrayed on the commercials. It's so off that I believe customers should be allowed to sue EA for false advertisement. Most people know the gameplay isn't going to be exact as a commercial advertises but looking back you almost want to say, 'holy shit what game are THEY playing?' It's that different.
Like the main review says, there is no real world roaming, so all there is to do is race. After awhile it seems repetitive. It seems like the same course over and over again just faster more graphic and decal whored up cars.
The main thing that really sets this NFS aside from the rest is the fact that damage actually does something for once. It just makes you pull out your, what seems like, endless supply of repair cards to fix the damage to your vehicle.
AI is halfway retarded. They break when they don't need to. And when you're behind two or three cars this poses a problem. The sequence of these events have a feel of a rigged nascar race. It gives the chance of the slower cars to catch up and take you over in order to create an even bigger wall of 'stop - go' computer cars for you to run into.
The buying of parts is a little unnecessary. It was a sad attempt to copy the Forza franchise and it was a failure because there is no such thing as a 47 thousand dollar acura engine for an integra, etc.
One small gain from this game is the fact that you have quite a bit of control over the setup of the cars parts. But then again, that's about the only thing.
I strongly suggest not buying this game. It feels like all you do is race the same courses over and over again in a futile attempt to become the 'fast and furious street racer of all time'. Get Call of Duty 4 instead.