Private Ross is driving a car with plates that begin with "VA". VA stands for "Volkes Armee" the East German Army. (US owned cars in West Germany/Berlin had special plates, and West Berlin German cars had tags that began with "B".)
The East Berlin Police Headquarters has a Volkswagen Kubelwagen parked in front of it in 1961. Volkswagen didn't re-introduce the Kublewagen until 1969, and originally for the West German Army and general public.