We stopped in a service area on the autobahn near Ulm last week. When we returned to our car after tea a police car was obstructing our exit. The policeman said the slight window tints on the front doors (installed by a previous owner) must be removed before we could proceed. My passenger and I are both in our late sixties. It was very difficult for us to remove the films just with our fingernails. It took nearly an hour and he watched as we struggled. It was humiliating and we were cold. We were also fined 120 Euros. He used no meter to measure the film. Just his own arbitrary decision. We had no idea we were breaking the law. Was his behaviour and on-the-spot fine correct please?