Access all tracks
Hold R1 and L1 at the title screen, then hit square, square, square, X, triangle, triangle, square, X.
Unlock All Cars
Hold R1 and L1 at the main title screen and hit triangle, X, X, circle, X, circle, triangle, X.
All track editor features
Win all the Arcade Circuit and Slalom Series races in either first, second, or third place.