Kabinenroller is a sort of a precursor to microcars of the 70s when afaik more models started appearing, instead of straight-up cabs-on-scooters of the 40s/50s. Notably, ‘Kabinenroller’ means precisely ‘scooter with cabin’.

It was also featured as Sam Lowry's car in ‘Brazil’: https://youtube.com/watch?v=iTYUPuZGbes