Lap Time of Zero Seconds:
Start a trial mode race and press Start + Select + A + B together just as the flag is waved for a lap time of zero seconds to be counted.

Instant 1st Place on Championship Mode:
Get into 1st place on a championship race and Press Start + Select + A + B together to finish 1st place instantly!

All Races & All Cups:
In the password column type in Muttley to unlock all racers and all cups.

Thanks to Revolution readers David Sharrock and Daniel Ericsson!