3. NSU Spider
Before even the Mazda Cosmo, this is the car that started it all. The NSU Spider was the first production car ever to be powered by a rotary engine thanks to a single 498 cc rotor that produced 50-54 hp. Mounted in the back, the rotary engine was selected due to its diminutive size; perfect for a tiny roadster.
The Spider itself was not a great car and the one rotor motor proved to be unreliable. However, it did blaze the trail that allowed every other vehicle on this list to be produced, and that alone is worth a lot of recognition.