Get The Gold Racer
Enter the exhibition mode, and select driver williams. Now change his name to PYRITE. Return to the start screen then go back to exhibition mode. A new gold driver will be available in exhibition time trial and two-player modes.
Bonus track
Enter exhibition mode and select driver williams. Now change his name to VACATION. Return to the start screen then go back to exhibition mode.
Get the silver racer
Enter exhibition mode and select driver williams. Now change his name to CHROME. Return to start screen and go to the exhibtion mode. A new gold driver will be avalable in exhibition mode in Time Trial, and two player mode.
Limo
At car select screen press up on the D-pad, Down on the D-pad ,left Right, Z Z, Top-C bottom-C
Killer Rats
Hold L & R and press zzzz.
New York cabs
Press R L Z Top-C Bottom-C Top-C