At the main menu choose "Single Player", then select "Time Trial" Enter the name, then return back to the main menu to see the new option, CHEATS. It's under Special Features.
Password
Effect
MARK
Unlock Everything, and Ghost Mode to Disable Collision Detection
BGM
See the Game Credits
Unlockables
Unlockable
How to Unlock
Spirit car
First place in Dining Room track in 3V class
GT Sport car
First on 3V and 6V class in championship mode
Harrier car
First place in Dining Room track in 3V class
Eagle car
First place in Dining Room track in 3V class
Bedroom car
First place in Dining Room track twice in 3V class
Choose any given letter by the game title you need to find Xbox cheats or Codes for.