California Speed cheats and cheat codes for Nintendo 64

Change the screen position
While playing the one player race, hold L + R + Start 
on controller 2 and move the Analog-joystick.

Unlock tracks:
Clover track: Finish week two of the Sport Series.
Fuji track: Finish week three of the Sport Series.
Oval track: Finish week two of the Heavy Series.
San Andreas track: Finish week three of the Heavy Series.
California track: Finish week five of the California Cup.

Unlock cars:
Camper truck: Finish the Heavy Series with the Ol' truck.
Dozer truck: Finish Do The State with the Semi truck.
Five-Oh car: Finish the Sport Series.
Forklift car: Finish the Light Series with the Insect car.
Insect car: Finish the Light Series with the Squirrel car.
Mano car: Finish the Sport Series with the Predator car.
Mountain Dew truck: Finish the Heavy Series.
Ol' truck: Finish the Heavy Series with the Mountain Dew truck.
Predator car: Finish the Sport Series with the Five-Oh car.
Semi truck: Finish Do The State.
Squirrel car: Finish the Light Series.