I agree that this is simply a heavily retouched rendering, but that doesn't mean it wasn't intended to become an actual car at some point. I'd also agree that the styling points to Germanic or Czech origins...
Otto, it looks like the drawing was created 'in period' to me (the shoddy editing around the bottom of the car is my own) but I suppose it could be a total fabrication meant to mislead people. The question still stands though, if not 'what is it?' then 'What does it purport to be?'