You did say it was not from Germany as such, but does that mean it was based on a German car?
You're looking at the correct hint, wrong answer!
So a German proposal based on a foreign car?
Not that either! Basically the car is the proposal in and of itself, not to provide a base for anything else. There is something special in the idea behind this vehicle.
By Karmann?
Not Karmann, no.
The designer did not go on to work in the design process of cars, but did remain in the automotive field in a related way.