That's the Fedorov Baikal...my fingers are still aching having to go through the J2mc listSorry, but not German. European though. First flown around 1986/1987.
Donot know about the car. My guess it is a homegrown product.
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https://imgur.com/a/9hmY4dnHi Carlo
The Baikal from USSRS it is. Design of Vladimir Egorovich Fedorov. Reportedly the engines caused problems and the test programme was cut short.
Mr. Fedorov later founded the Aviatroitel company which produced the AC- series of high performance gliders and motor gliders.
Looking forward to your next challenge Carlo !