Overhead view
Press [Up], [Down], [L], [R], [Select]
at the title screen. Enable the new "Mystery Mode" selection
at the bottom of the options screen.
Drive Boss car
Press [L], [R], [Up] at the title screen.
A rumbling sound will confirm correct code entry. Start a normal
game. After reaching the Boss, you will be driving his car.
Alternate car colors
Highlight a car at the selection screen then press
[A] + [Select] + [Start]. You will now be able
to choose a color for your car.