Enter these codes at the main menu, an engine reving will confirm correct code entry. You can only enter one code at a time and you will have to re-enter codes for each race:
Always have turbo -- R2, L1, Square, Triangle, R1, L2, L1, R2
No textures on cars -- L1, R1, L2, R2,L1, R1, L2, R2
Tiny Cars -- Square, R2, L2, Triangle, Triangle, L2, R2, Square
Big Tires -- Square, Triangle, Square, Triangle, R1, R1 L2, L2
"dude" Sounds --R2, R1, L2, R2, Square, Triangle, L1, R1
In the race road to rustwell, after the jump that gets you wicked air, you go through the first barn thing you see the jump DON'T go off it. Yougo around the high end of it and hit the lighter colored piece of the house to your right and ram it. Then you see the ROCKBUSTER. Run into it and you have it!
Unlock Tow Jam - TWJM Unlock All Secret courses and cars - PWDTST