MX Superfly featuring Ricky Carmichael Cheats
Begin the game in the two-player mode. Take the 1st controller and hold L2 + R1 and press Up, Down, Left, Right Triangle. Then get someone else to pick up the second controller and hold L2 + R2 + Triangle + X.
Complete the whole career by placing qualifying positions and finally finishing your last race in 1st place. You'll have the option to change your CC on any bike in any mode.