Select the "Game Modes" option at the main menu. Then, select "Fight To The Top". Enter one of the following case-sensitive first and last names at the driver information screen to activate the corresponding cheat function.
Old Spice Fantasy track and all cars and drivers in all four divisions:
Enter KeepCool as a first name and SmellGreat as a last name.

All Chase plates:
Enter ItsAll as a first name and ForMe as a last name.

10 million fans:
Enter AllBow as a first name and ToMe as a last name.

Level 10 Prestige:
Enter Outaa as a first name and MyWay as a last name.

$10 million:
Enter GiveMe as a first name and More as a last name.

Unknown:
Enter MoMoney as a first name and BlingBling as a last name.