Successfully complete the indicated task to unlock the corresponding car:

Police Austin Mini Cooper: Win Easy Race mode with the Austin Mini Cooper. 
Police Fiat A112 Abarth: Win Easy Race mode with the Fiat A112 Abarth. 
Police Lancia Delta: Win Easy Race mode with the Lancia Delta. 
Police Renault 5: Win Easy Race mode with the Renault 5. 
Police Volkswagen Golf GTI: Win Easy Race mode with the Volkswagen Golf GTI. 
Taxi Austin Mini Cooper: Win Medium Race mode with the Austin Mini Cooper. 
Taxi Fiat A112 Abarth: Win Medium Race mode with the A112 Abarth. 
Taxi Lancia Delta: Win Medium Race mode with the Lancia Delta. 
Taxi Renault 5: Win Medium Race mode with the Renault 5. 
Taxi Volkswagen Golf GTI: Win Medium Race mode with the Volkswagen Golf GTI. 
Toy Dog: Win Hard Race mode with any car.