Cheats
At the Main Menu, press the following:

Aston Martin V12 Vanquish	R2, Right, R2, Right, Triangle, Left, Triangle, Left
Black & White	R1, L1, Left, Triange, Left, Left, Left, L1
BMW Z8	Square, Right, Square, Right, R2, Triangle, R2, Triangle
Carrera GT NFS	R2, Triangle, Triangle, Triangle, R1, Square, Square, Triangle
Championship Event 31	L1, Square, R2, R2, R2, R1, L1, Square
Chrome Cars	L2, R2, Left, Square, Left, Left, Left, R2
Clk GTR NFS	Triangle, Left, Left, Left, L1, L2, L2, Left
F1 LM NFS	R1, Square, Square, Square, R2, left, left, Square
Ferrari 360 Moderna	Left, Square, Square, Square, R1, L2, L2, Square
Ferrari F50	L1, Triangle, L1, Triangle, Right, L2, Right, L2
Ferrari F550	L1, Square, L1, Square, Right, R1, Right, R1
Ford TS50	Right, Left, Right, Left, R2, Square, R2, Square
Ford TS50	Right, Left, Right, Left, R2, Square, R2, Square
Heavy Fog	Triangle, Square, Right, R2, Right, Right, Right, Square
HSV Coupe GTS	L1, L2, L1, L2, R1, Triangle, R1, Triangle
Lamborgini Diablo 6.0 VT	Right, R2, Right, R2, R1, L1, R1, L1
McLaren F1 LM	Square, L1, Square, L1, Triangle, Right, Triangle, Right
Mercedes CLK GTR	R2, R1, R2, R1, Left, Triangle, Left, Triangle
Murcielago NFS	L1, R2, R2, R2, Left, Square, Square, R2
Porsche Carrera GT	Left, Right, Left, Right, R1, R2, R1, R2
Porshe Carrera GT	Left, Right, Left, Right, R1, R2, R1, R2
Pursuit Mustang Cobra R	Left, Square, Left, Square, R2, R1, R2, R1
R/C Car	Right, Triangle, L1, R1, L1, L1, L1, Triangle
Corvette V06	Left, R2, Left, R2, L1, R1, L1, R1
Ferrari 360 Spider	R2, Square, R2, Square, Triangle, L2, Triangle, L2
Porche	Square, L1, L2, L1, L2
Lotus Elise	Triangle, R2, Triangle, R2, Left, Square, Left, Square
McLaren F1	Triangle, L1, Triangle, L1, R1, Left, R1, Left
Vanquish	R2, Right, R2, Right, Triangle, Left, Triangle