I'm sorry to disappoint you all a bit. This is only a toy, not a real car!
Heinrich Kertész was a novelty dealer, see some examples below.
The ad says that the Rapid is steerable, and self-moving in circles, very entertaining for young and old. Its price was 1.25 Gulden the piece, 3.30 Gulden for three of them. One Gulden was two Kronen, for which you could buy the horse blanket and get some small change back
Don't worry, that was an amusing puzzle.