As requested, the Steinmetz Commodore Jumbo.
The Commodore B series was like the A series briefly used in motorsports, and the extreme "Jumbo" Commodore raced in the 1974 "interserie". It used a 6.0-litre V8 engine and had large wings which almost made it unrecognizable as an Opel. It never enjoyed much success despite of its massive powerplant and impressive output.
Source: Wikipedia