Complete the following achievements to unlock Xbox Live Gamerscore points.
Select "Driver DNA Lab", then choose "Celebrity Face Off". Defeat the indicated driver in all three of his challenges to unlock the corresponding car.
If you need money fast, try spectator betting. You can get amounts of $300 000 to $10 million. To get this money easily, bet on a 20:1 driver on the maps "Gladiators Shadow" and "Lethal Rush" Make sure that they are not Extreme Nitrous events. When betting, place small amounts first until you get the hang of the cheers and boos.
In the DNA menu, from main menu, go to cheats and codes. Type in the following codes to race in that challenge and unlock the corresponding car.