Cops'n Robbers is about the age-old struggle between good, evil, and beer truck.
Unused Car#
A small car is present in the same graphics ROM as the beer truck. Presumably, these cars would drive on either side of the truck, moving at a slower or faster speed than said truck. It might have absorbed the players' shots like the beer truck does. However, there's no code anywhere in the game to move or even display these cars.
(Source: Original TCRF research)