4 Wheel Thunder Cheats (Dreamcast)

Successfully complete outdoor arcade mode to unlock the Scandinavia, Jordan, Greece
Sunset, Norway, Iceland, Atlas, Alps, and Canada Rain tracks.

Pause game play, then press X + Y.

Successfully complete championship mode to unlock the Atlas Sandstorm, Corsica Rain, Far
West Night, Iceland Snow, Scandinavia Storm, and Norway Night tracks.

Successfully complete indoor arcade mode to unlock the Indoor Scandinavia, Indoor Far
West, Indoor Iceland, Indoor Atlas, and Greece Daylight tracks.

This trick assumes the game is under the default controller setting. When "Go" appears
during the pre-race countdown, press R + A. If done correctly, your truck will get a
faster start and a four-second boost.

After finishing a race in Championship mode, save your game in case a you get to try for
the jackpot. If you don't win it on the first try, simply reload your game in the options
menu and keep trying until you win.

Pause the game, hold the left trigger, enter the following: 
  Upx4, A, X, Upx4, A, X, Upx4

  Note: The code works best when entered slowly.

  Once the code is enabled, just hold down "jump" to stay in the air.

Successfully complete championship mode to unlock three hidden monster trucks.