How many cars are there in need for speed underground?

first go to underground mode and play races.next you earn style points then have fun

The Nissan skyline is the fastest

Need for speed Carbon for Nintendo DS has 15 cars.

Sign sponsers and get new slots for new cars.

Basically beat every race and URL race. After that the Boss wants to race you. If you beat him, you beat the game, and unlock every car.