Use the following cheats to enable the corresponding cheat function:
All tracks: at the options screen, enter XXY
Easy car handling: at the car selection screen, hold X and press Enter
Ultimate Ghost car: in time attack mode, hold X + Y and select 3 Laps
Lake Side track: at the main menu, press X + Y, then select any game mode
Mirror tracks: at the game select screen in arcade mode, hold Y and press Enter
Full screen: at the car, race, or mode selection screen, hold X and press A