Ro80 was made by Audi, but still with NSU badge until about 1977.
Wankel engine also licensed to Mazda, for Gasoline engines; Norton, for motorcycles; Rolls Royce for diesels; Curtiss-Wright for aero engines.
Mazda we all know, Norton built a 'bike which was supplied to the police in UK, Rolls abandoned the diesel project - they tried a 2-rotor layout with one as a compressor for the other, and I think Curtiss-Wright still build a stationary engine.
In partnership with NSU, Citroen produced about 840 units of 2-rotor car, the Bi-rotor, in 1974/75, with the GS body, but sales figures were a disaster.
Mercedes produced a prototype 3-rotor engine in a 2 seat sports car, which toured dealers in UK and elsewhere in the late 70's. It looked amazing. I met one coming towards me one day, and nearly drove off the road!
I collected my first Ro80 from the factory in Neckarsulm in 1968 and regretfully sold it a year later. I bought another in 1973, which I spun and wrecked in Greece in 1983 - I drove it back to Spain, though. I found a good one to replace it in 1984, and broke the other for parts.
The torque converter siezed, stripping the flywheel key, and the engine reached some unholy rpm as I pulled away from a toll gate in Spain one day. The tip seals ripped out and perforated the rotor housings - total destruction.
I fitted the engine from the wrecked car, but this started smoking badly, a sign of bad seals. I stored it away, after a bare body restoration and 8 coat paint job.
Last year I installed a Mazda 13B rotary engine, modified to take 2 very large SU carbs, and with modified rotor seals. This has about 170 bhp, a big improvement on original 115, with no special tuning. Fuel economy is better than original too, about 20 mpg compared with 14 or so before. (US gallons). Car has done just over 120mph on the German Autobahn, but suffered from fuel starvation, needs a bigger fuel pump.
The car is on
www.nsu-ro80.com click FOTO ALBUM, then Dick Flower.
Be interested to hear from any other owners, also to find any Ro80 Forums in English