In several episodes where Semir Gerkhan is driving a 1998 BMW 3 Series, the car is suddenly replaced by a 1992 or 2003 model during car chases and stunts.
In one episode in the fourth season, they want to get into a military base, which is denied by the sentry at the gate. In Germany, every police officer can enter any military base and even get a free meal in the cafeteria for the enlisted men.