At the options screen, type "XXY".
At the main menu, type "XYZYX", then select a mode. Highlight the Celica on the car selection screen and press [Down] to select the AT transmission, and the Delta to select the MT transmission.
Easier Handling Car
At the car selection screen, hold X and press [Enter] to select any car.
Ultimate Ghost Car
Select time attack mode. Then, hold X + Y and select "3 Laps".
Lake Side Track
At the main menu, press X + Y, then select any game mode.
At the game select screen in arcade mode, hold Y and press [Enter].
At the car, race, or mode selection screen, hold X and press A to remove the dashboard and display.