Is it a the Maico 500 with a body by Wendler?
That's the one!
![:applause:](https://www.autopuzzles.com/forum/Smileys/default/applause.gif)
Recently this car was discussed, though not shown on a very common source.
Coincidentally I've found it in a German book about Cabriolets (and unexpectedly not in the Wendler book!) described as the Wendler bodied Maico 500 which was never shown to public. No doubt the plastic bodied Beutler Maicos (Coupé and Cabriolet) were a lot prettier than this ungainly Wendler attempt.
Unfortunately they weren't successful either as Maico (cars) went bust a little later. Only four Beutler Maico 500 conversions had been built in 1957.