To unlock these customised DNA lab cars you must first enter the code which unlocks a special challenge and then you must beat it to get the car.

Unlock BMW Z4 Roadster:
Enter the code GVDL

Unlock Holden Monaro:
Enter the code RBSG

Unlock Hyundi Coupe 2.7 V6:
Enter the code BSLU

Unlock Ascari KZ1:
Enter the code KNOX

Unlock Audi TT 1.8 Quattro:
Enter the code YTHZ

Unlock Infinity G35:
Enter the code MRHC

Unlock Infinity G35 (Red Design):
Enter the code MNCH

Unlock Koenigsegg CCX:
Enter the code KDTR

Unlock Nissan 350Z:
Enter the code PRGN

Unlock Saleen S7:
Enter the code WIKF

Unlock Seat Leon Cupra R:
Enter the code FAMQ

Unlock Mitsubishi Prototype X:
Enter the code DOPX

Unlock Nissan Skyline R34 GT-R:
Enter the code JWRS