Cheat mode
 
 At the "Press Start" screen, press L + R, C-Left, C-Right, L + R.
 Press Start, then at the mode selection screen, hold Z and tap L
 until "Cheat mode" appears at the bottom of the screen. Cheat mode
 includes special modes and the option to unlock bonus cars. -From:
 LKn9468138@aol.com 
 
  Game Shark Codez:
 
                     
  Unlock All Tracks   
  80140D1A 0070
                     
  Unlock All Cars     
  80140D1F 003F
                     
  Unlock Champ        
  80140D28 0001
                     
  Enable Expert Times 
  80140D1C 0031