stages, A, B, and C, while in production, and most Volkswagen-sourced parts were replaced by Porsche-made parts. Beginning in 1954 the 356s engines started utilizing engine cases designed specifically for the 356. The sleek bodywork was designed by Erwin Komenda, who also had designed the body of the Beetle. Porsche's signature designs have, from the beginning, featured air-cooled rear-engine configurations (like the Beetle), rare for other car manufacturers, but producing automobiles that are very well balanced. In 1964, after a fair amount of success in motor-racing with various models including the 550 Spyder, and with the 356 needing a major re-design, the company launched the Porsche 911: another air-cooled, rear-engined sports car, this time with a six-cylinder "boxer" engine. The team to lay out the body shell design was led by Ferry Porsche's eldest son, Ferdinand Alexander Porsche (F. A.). The design phase for the 911 caused internal problems with Erwin Komenda, who led the body design department until then. F. A. Porsche complained Komenda made unauthorized changes to the design. Company leader Ferry Porsche took his son's drawings to neighbouring chassis manufacturer Reuter. Reuter's workshop was later acquired by Porsche (so-called Werk 2). Afterward, Reuter became a seat manufacturer, today known as Keiper-Recaro. The design office gave sequential numbers to every project (See Porsche type numbers), but the designated 901 nomenclature contravened Peugeot's trademarks on all 'x0x' names, so it was adjusted to 911. Racing models adhered to the "correct" numbering sequence: 904, 906, 908. The 911 has become Porsche's most well-known model – successful on the race-track, in rallies, and in terms of road car sales. It remains in production; however, after several generations of revision, current-model 911s share only the basic mechanical configuration of a rear-engined, six-cylinder coupé, and basic styling cues with the original car. A cost-reduced model with the same body, but with a 356-derived four-cylinder engine, was sold as the 912. In 1972, the company's legal form was changed from Kommanditgesellschaft (KG), or limited partnership, to Aktiengesellschaft (AG), or public limited company, because Ferry Porsche came to believe the scale of the company outgrew a "family operation", after learning about Soichiro Honda's "no family members in the company" policy at Honda. This led to the establishment of an executive board with members from outside the Porsche family, and a supervisory board consisting largely of family members. With this change, most family members in the