Cheat mode
Hold [L] and press [A], [Y], [X], [B], [Left], [Start] at the main menu to unlock all trucks, all tracks, and disable the timer.
Ice cream trailer
Hold [L] + [R] + [X] + [A] + [B] + [Y] + [Start] at the trailer selection screen.
Full pause screen
Press [Start] to pause game play, then press [A] + [X] + [B] + [Y].
Bonus parking levels
Successfully complete each of the four parking levels to unlock an additional parking level. Successfully complete the bonus parking level to unlock a sixth parking level.
Nippon Maru
Successfully complete arcade mode with all four characters.
Lizard Tail
Successfully complete the game with all five trucks (Asphalt Cowboy, Stream Line, Long Horn, Highway Cat, and Nippon Maru).
Bonus trailers
Successfully complete arcade mode with all four characters to unlock two bonus trailers in score attack mode, versus mode, and arcade mode (if the Nippon Maru is selected).