Select Earn Your Stripes mode. Then, enter one of the following case-sensitive first and last names at the driver information screen to activate the corresponding cheat function:
Enter "Checkered" as a first name and "Flag" as a last name to unlock all cars in Chase mode.
Enter "Race" as a first name and "ThePack" as a last name to unlock all fantasy drivers.
Enter "EASports" as a first name and "Car" as a last name to unlock the EA Sports car.
Enter "Walmart" as a first name and "EveryDay" as a last name to unlock the Wal-Mart track and car.
When qualifying for a Daytona or Talladega race, turn off braking assists. This will allow your car to reach maximum speed, resulting in a pole position every time. This works in all race modes.
Select the Gold (Hard) challenge for Follow The Leader. When the race starts, find the best spot to ram your car into the wall (head-on works best). You have to hit hard enough to destroy the suspension or you will get a "Failed" message, saying you hit the wall too much. If done correctly, you will pass the challenge. -From: Tribal