Wild guess time. The "castle" (Schloss) is Schonbrunn Palace in Vienna (Wien...the closest I got to there was Salzburg in the late 60s) and the sinister car is a Steyr-Puch 50 built by slave labor under the the "command" of Georg Meindl.
Research on this has taken me WAY far afield from cars and puzzles. I think I'm through with this one.