Inspired by the recent appearance of a sextet of C111's at Techno-Classica Essen, just a random thought.
So M.B. had dropped the Wankel concept and along came a series of rugged, reliable and very quick diesel powered versions. In various forms they lapped Nardi at an average in excess of 155mph over 64 hours (!), then a return to average nearly 200mph over 500 kms before the final version with Project 400 WM look-alike bodywork topped out at 250 mph (appropriately). All of this with fuel economy (allegedly) the happy side of 15 mpg (18L/100km).
OK the M.B. board didn't have a great enthusiasm for motorsport in the late 70's but it sounds like a great recipe for an endurance racer to me...