On the Scotland Highland Moors level in multi-player mode, drive backwards and continue until you see the castle bridge. Go under it until you see the "!" icon which activates a certain part of the level. This will trigger the bridge of the castle to fall down. Once it has fallen, go back to the bridge and drive under and into one of the sides of the bridge. If hit in the correct place, you should be launched very high into the air. NOTE: This may cause the game to freeze.