In the purple Opel Manta of the character Mario, in a close-up shot (of him having sex with "Das junge Mädchen"), it can be seen that the Opel badge has been taken out from the middle of the steering wheel. However, in other shots, the badge is in its place, not having been taken out.
At the beginning of the movie in front of the supermarket the boom mic and the camera are reflected in a car window.