Unlock all cars:
While selecting your car, click and hold the Left thumbstick and press L, R, L, L, L, R, R, R, L, L, R, R .

Audi S4 Avant:
Beat the first six Blitz races in Paris.

Audi TT:
Finish the Special Agent job in Paris.

Cadillac Escalade:
Finish the Limo Driver job in Washington D.C.

Cement Truck:
Beat the first six Checkpoint races in Washington D.C.

Chevrolet Corvette Z06:
Beat checkpoint race 10 in Washington D.C.

Chevrolet SSR:
Beat the first three Blitz races in Washington D.C.

Chrysler Crossfire:
Beat Blitz race 10 in Washington D.C.

Chrysler PT Turbo:
Finish the Rental Car Driver job in Washington D.C.

Dodge Viper SRT-10:
Finish the Private Eye job in Washington D.C.

Fire Truck:
Beat the first six Checkpoint races in Paris.

FLE:
Finish the Delivery Man job in Paris .

Freightliner Century Class S/T:
Beat the first six Blitz races in Washington.

Hummer H2 SUV:
Finish the Salesman job in Washington D.C.

Koenigsegg CC:
Finish all jobs and win all races.

Limousine:
Finish the Chauffeur job in Paris.

Lotus Esprit V8:
Beat Blitz race 10 in Paris.

Mini Cooper S:
Finish the first three Blitz races in Paris.

Paris Bus:
Beat the first three Checkpoint races in Paris.

Paris Police:
Finish the Police Officer job in Paris.

Saab 9-3 Turbo:
Beat Checkpoint race 10 in Paris.

Taxi:
Finish the Taxi Driver job in Paris.

Washington Bus:
Beat the first three Checkpoint races in Washington D.C.

Washington Police:
Finish the Police Officer job in Washington D.C.

Thanks to Revolution readers Martin Brodeur, PoopyPants and SamSam!