marge and otto in the half pipe

in the episode where marge chases the school bus so she can get bart and lisa on it, both vehicles go into a halfpipe and start doing skateboard tricks. when they launch out, both cars have a design on their bottoms (simulating the deck art of real skateboards). does anyone know what these designs were? i know the school bus' looked something like a "world industry board". (world industries is a skateboard company for those of you who dont skate)