NSU pioneered use of the Wankel / rotary engine in production automobiles when it released the Prinz Sport based Spider in 1964. While the rotary was certainly a major advancement in engine technology, NSU hadn’t quite worked all of the proverbial bugs out of it. Therefore, the Spider became one of he most infamous cars the automotive world has known due to the power plant being prone to self-destruction after only a few thousand miles. This did not, however, make NSU give up.
In 1967 NSU released the Ro80 with a new two-rotor engine. This unit was more powerful than the Spider at a very respectable (for the time) 115 horsepower at just under one liter. That’s right, over 100hp per liter – which all things considered is quite amazing. Adding to the sedan’s innovative technologies were a 3-speed, semi-automatic, front-drive gearbox which was very similar in operation to Porsche’s Sportomatic transmission. The Ro80 also sported four-wheel disc brakes, which were mounted inboard (as the later Audi 100 C1 would feature) and power steering, which was relatively rare in the mid-1960s.
The body proved to be ahead of its time as well, in both styling and aerodynamics. It was designed with large glass areas, smoothly integrated headlights, and a drag coefficient of 0.35cd. Claus Luthe, who also styled the NSU Prinz, K70, and a later, VW, and BMW models, penned all of this. (Luthe was also convicted of killing his son in 1990, but that, of course, is another story) Styling remained relatively unchanged throughout the life-span of the model aside from a slight rear-end updating which gave it larger taillights and moved the license plate above the bumper. By then, the drag coefficient had dropped even more to 0.34cd.
Unfortunately, despite initial strong sales, fate struck the Ro80 in much the same was as its rotary predecessor the Spider. Premature rotor seal failure was very common and generally fatal to the power plant at around 30,000 miles. This took a high toll on NSU as the reputation of the cars reliability became increasingly bad. That coupled with the costs of warranty repairs left the company in financially dire straits. Volkswagen purchased NSU in 1969 and merged it with the Auto-Union division that it had acquired earlier from Daimler-Benz. Audi NSU Auto-Union AG continued to produce the Ro80 until 1977 when the brand was finally discontinued, though officially, the division name remained for several years and many of the innovations lived on in Audi models. So ended over 90 years of NSU vehicle manufacture, from bicycles to motorbikes to cars.
Beautiful landscape in this Zastava ad. 
... and then they just stopped trying. I believe they taped a photo of the car to a page out of an Eastern Bloc adult magazine and went to press...
