The C111 was a series of experimental automobiles produced by Mercedes-Benz in the 1960s and 1970s. The company was experimenting with new engine technologies, including Wankel engines, Diesel engines, and turbochargers, and used the basic C111 platform as a testbed. Other experimental features included gullwing doors and a luxurious interior with leather trim and air conditioning.
The first version of the C111 was completed in 1969. It used a fiberglass body shell and had a three-rotor fuel injected Wankel engine mounted in the middle.
Source: Wikipedia