Here are some cheats and tips for the game Cars.
All levels and 90 Bolts:
Press Up(2), Down(2), Left, Right, Left, Right, B, A at the
“Press Start” screen.
All cars:
Press Right, Down, Right, B at the “Press Start” screen.
Radiator Cap secret circuit:
Press Left(2), Right(2), B(2), A at the “Press Start” screen.
All car colors:
Press Up(2), Left, Right(2), Left, Down(2) at the “Press Start” screen.
All screenshots at the Drive-In:
Press Left, Down, Right, A at the “Press Start” screen.