Forza Motorsport 3

Next to a driver level, there's also a car level. Cars start at a level of 0, and can be increased to 5.

Every car has a certain experience point requirement to level up. You could either:
- Use one car for many events
- Do an endurance race. You'll probably level your car to 5 straight away considering you get a very high amount of experience points (credits) at once.

Good Luck