For consoles:
Split / Second: Cheat Codes [PC + PS3 + X360] Free Download
Disney XD car:
To open this special machine, in the initial screen (where it says Press Start), press the following key combination: X, Down, X, Down, X, Down.
AMX Coyote:
To open this special machine, in the initial screen (where it says Press Start), press the following key combination Left, X, Left, X, Left, X, Left, X, Left, X, Left, X, Right.
Computer Spiele car:
To open this special machine, in the initial screen (where it says Press Start), press the following key combination X, Up, X, Up, X, Up.
For PC:
To open a special machine Disney xd car in the initial screen (where it says Press Start), press the following key combination:
up, left, right, right, left, left, right, right
All cars will be available in the quick race menu.