Oh dear, you are right. I had two different sources, Frieder Bach's book "Fahrzeugspuren in Chemnitz Teil 2" and a newspaper clipping (see below) which both spelled the name Schmotz. But I've found your source too, and the old photo verifies Schmoz (as well as another source about his aircraft ambitions). And yes, the car is based on a VW Typ 3 and one of 3 (or 5) cars built by Rudolf Schmoz. With your source it will be easy now to find its name which is written partly at the front and another part at the rear of the car. Still locked for you.