When racing dirtbikes press Left, Left, Up, Up, Right, Right, Down, Down, Square, Triangle, Cross
Big Air in Dirtbike Mode
At the title screen press R1, R2, Up, Left, Triangle
Bonus Track
At the main menu press Up, Up, Up, Right, Left, Triangle, X
Faster Bike
At the main menu press Circle, Square, Right, Left, L1, R1, X
Other racers limited to 50 km/h.
At the main menu press R2, L2, Right, Up, Left, Triangle, Circle, Square, Cross
Unlock extra tracks and championship mode.