The Porsche 942 was a special edition of 928 submitted by the company as a gift to Ferry Porsche on his 75th birthday in 1984. Also known by name 928-4, 928S. Had additional 254 mm wheelbase than the normal 928 production model, including an extended roof over the rear seats to better accommodate tall passengers, headlights very advanced technology, the motor 5 liter 32 valves before introduced to the U.S. market and the front and rear of the S4 model two years before going into production.

Three years later, in 1987, the 928 extended 25 cm to 4.77 meters, which had been presented to the company’s founder in its 75th birthday, was presented as a “Feasibility Study”. In 1984 the car passenger access had been resolved with two normal doors. In the new study the vertical pillar was deleted and the second pair of doors open in opposite directions. The new doors, narrower leaf apparently opened in the same way that The Mazda RX-8 in the early 2000. “H50 study” at the time he disappeared, leaving few traces. Two decades later, with the launch of the Porsche Panamera, and larger four-door prototype 928 four-door 1987 became more important.

An extra car was a manual with data comparisons between special and standard version. Weight was increased in all four doors with 75kg. The turning radius was extended to 12.5 meters. Porsche also increased the rear track by 25 mm to 1,564 mm, while the front track width was the same. The designer of the four-door was Anatole Lapine.

Porsche since 1986, with the company car preparation produced some 928 special AMG gauges more. Unlike the 942, they had the usual optical illumination at 928. One of them was presented to the founder of American Sunroof Corporation (ASC) and CEO Heinz Prechter. ASC was later partly responsible of making Porsche 944 S2 cabriolets.

Porsche Racing Department never officially entered or prepared the 928 in competition or officially. Only once he decided to clear the 928 genes racing. Prepared Porsche which would be called 928GTR to compete against the then dominant 911 (993GTR) on the track. In order to present the 928 without offending the sensibilities of their traditional customers 911/993GTR, Porsche was ceded to the private race team Max Moritz Racing, customer associated with Porsche for a long time and based in Reutlingen, to get him into the Cup as a semi-official car.

It was no surprise that the chosen drivers were: Bernd Mayländer, Manuel Reuter (Porsche Pilot tester) and Harm Lagaay (then head of the Porsche Design Studio). Vittorio Strosek sponsored Max Moritz with its ultralight components and sport exhaust. The car was officially entered by Porsche-Club-Schwaben. The approved minimum weight and had to be done was 1,370kg (3,000 lb).

Lagaai reported that the car was very competitive and able to hold off most 993GTR, although the engine was just set, after being chosen from a sample set of high-performance engines in Weissach. In the last race of the season at Hockenheim ran with dry crankshaft. As the car also supposed to run in 1995, was prepared to continue their success in the competition in the 1995 season. A new engine was set, selected from the same batch of high-performance engines tuned as before. In 1995 the production of the Porsche 928 came to an end, and the car therefore did not run in the new season.

The late Max Moritz kept at 928 in his collection of historic cars. It was put into service again until after his death, when the family sold the car in October 2004 – with only 24,500km on the counter (Porsche Weissach is the only documented owner).