What year is this set in?

What year is this set in? My guess is mid-1970s, but being a German show it's hard to get a sense from the sets and backdrops due to the sheer volume of modern design and the amount of new construction (Berlin would have extensive new construction due to the war).

Anachronistically, a 1975 Cadillac de Ville appears in the background of a street scene. '75 was the first model year with square headlights, although it could have been an even later model. However, the news headline two Americans are shown watching is of Willy Brandt's resignation, which happened in 1974. So if it was '74, the car was wrong, but the news of Brandt's resignation wouldn't likely have been news in '75 or later, or at least not that big of a deal to two Americans. I would have been surprised if there were any Cadillacs of any recent vintage in Berlin -- the gas mileage alone would have made them impossibly expensive, and large Mercedes sedans likely far less expensive to buy.