In 1964 the Wankel Spider was launched with a convertible body based on the Sport Prinz, but few panels are interchangeable. The Spider was given a 497.5cc single rotor Wankel engine producing 50bhp. The world's first Wankel-engined production car. 2375 NSU Wankel spiders were produced until 1967. This little NSU pioneered Wankel car development and led to the twin rotor NSU ro80. Felix Wankel is supposed to have dreamed of an engine similar to the final design of the Rotary engine as early as 1919. In 1924 Felix had a laboratory where he began to experiment with Rotary engines, worked which was eventually funded by the Nazi government through WWII. Felix Wankel thus came to the attention of the burgeoning NSU motorcycle company in 1951 which was already famed for technical development and had won many World Grand Prix Motorcycle championships. The first NSU Wankel engine was presented in 1957, and further developed until it was fitted into the NSU Wankel Spider in 1964. Also in 1964 Comobil was founded as a joint venture between Citroen and NSU to develop the Wankel engine, and in 1967 Comotor was established as a join Citroen/NSU manufacturing plant for the Wankel engine. Mazda signed an agreement with NSU in 1961, and in 1967 launched the Mazda Cosmo sport with twin rotor Wankel engine. Mazda went on to sell more than a million Wankel-engined cars until 2012. Rolls-Royce, Daimler-Benz and Curtiss-Wright aircraft are some of the companies who did development with Wankel Rotary engines. However, the Wankel engine was apex seal problems, and also can use a lot of fuel and oil and give high levels of certain pollutants, and all these problems have largely inhibited take up of a very efficient form of Internal Combustion engine.