Unlockable: Nippon Maru Truck
To unlock the tight, double-stacked Nippon Maru Truck, go to the title screen. Press and hold X, then press Start. Keep holding X until you see the Mode Select screen. The Nippon Maru truck will be available once you choose a game mode.
Unlockable: Extra parking levels
Complete all four parking levels to unlock an fifth parking level.
Complete the bonus fifth parking level to unlock the sixth parking level.
Unlockable: Lizard Tail
Complete the game with all five trucks, including the bonus Nippon Maru.
Hint: Earn bonus parts
You can earn bonus parts by completting the parking mini-game after beating your rival in any Arcade destination race.
Unlockable: Bonus trailers
Complete arcade mode with all four characters. Two bonus trailers unlock in Score Attack mode, Versus mode, and Arcade mode for all trucks except the Nippon Maru.
Hint: Split stream boost
You can effectively draft behind trucks your size giving your truck a slight boost in speed.
Top Cheat Sites for 18 Wheeler: American Pro Trucker
