Save each time you qualify in season mode,so you can access your new tracks during your next game.
Enable Cheats
Set the Professional Laps to six and go to the main menu and press Circle, Circle, Square, Triangle, Triangle, Square, Triangle.
Make 'em fall!
You can make the other riders fall if you rise your motor bike by pressing either the R2 button, or the down button (you would prefer the R2 button, 'cause it speeds your bike). You do this when you are near the rider you want to make him fall (most preferable if you do it behind him).
Play your own music while racing
Pick any race in the game, when the race you picked starts, pause the game and open the Playstation lid, take the game out and put in any music cd you want to listen to and close the Playstation lid and the music will come on while racing.