It's named on several sites as a 1927 Chrysler Imperial Speedster. It's Austrian-owned, and that's about all I can tell you. It has been pictured on a Austrian retrospective event, but the captions say nothing about the history or specification of the car. My guess is that it's a 1927 Chrysler Imperial engine fitted into a specially-built lightweight chassis, possibly of more recent date.
(From the start, I couldn't understand how the car was so small - American sports cars of that era were still quite big, like the Stutz and Chrysler cars that raced at Le Mans. I can't believe that this puzzle car was built by the factory.)
PS Thank you Woodinsight for your gracious deference. And Mekubb for allowing me to proceed. I only wish I could have told you more.