Aston Martin V12 Vanquish:
R2, Right, R2, Right, Triangle, Left, Triangle, Left McLaren F1 LM:
Square, L1, Square, L1, Triangle, Right, Triangle, Right

(Submitted by: Despot) Lamburgini Diablo 6.0 VT:
At the main menu press: Right, R2, Right, R2, R1, L1, R1, L1.