18 Wheeler: American Pro Trucker
Books: Secret Codes 2003 - The Ultimate Code Book: Cheating Made Easy
Last Updated: 5/11/02.
Nippon Maru 
Bonus trailers
Bonus parking levels
Nippon Maru
Successfully complete arcade mode with all four characters:
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).
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.
