Need for Speed ProStreet

In Need for Speed ProStreet, "Speed Challenges are very much like a standard race, except that the courses you race on are designed to be extremely fast, with turns that slowly move from side to side that allow you to keep your foot on the gas at all times."
It looks like we get the ability to drive cars such as the new Skyline, Cayman, Turbo, M3, RS4, Elise, as well as a whole crap load of new (and old) yet slightly lesser cars.