From the listing for this 80’s Racing Porsche 962:

In the late eighties the Kremer brothers had a development of the 962, which was given the CK (C for Group C racing, the K for Kremer) designation. The Le Mans 962 CK6 featured a short tail, a centre-post wing and covered wheel arches which gave the Porsche a quite different appearance from the standard 962.

A unique opportunity to purchase one of the iconic Porsche 962 sportscars, in fantastic condition and stunning Leyton House livery. Originally built for the Japanese Sportscar Championship. Rebuilt in period by Kremer, and raced successfully more recently – eligible for all Group C racing and Le Mans Legend events, recently converted to Motec electronics to enable better engine management of the Air-Water engine.

From Wikipedia:

The Porsche 962 (also known as the 962C in its Group C form) is a sports-prototype racing car built by Porsche as a replacement for the 956 and designed mainly to comply with IMSA’s GTP regulations, although it would later compete in the European Group C formula as the 956 had. The 962 was introduced at the end of 1984, from which it quickly became successful through private owners while having a remarkably long-lived career, with some examples still proving competitive into the mid-1990s

Privately built 962s

A Kremer 962CK6.

Beyond minor modification, some private teams reengineered the entire car. One noted problem of the 962 was a lack of stiffness in the aluminium chassis, leading some teams to design new chassis, and then buy components from Porsche to complete the car, although some also had unique bodywork as well. Some teams would then offer their 962s to other customer teams.

Among the most popular privately built 962s was that from Kremer Racing, termed the 962CK6, which did away with the original aluminium sheet tub of the original Porsche chassis, replacing it with a carbon fibre tub. Eleven were built, campaigned by Kremer and other teams. John Thompson designed a chassis for Brun Motorsport, eight of which were built and helped the team take second in the World Sportscar Championship in 1987. Thompson would later build two chassis for Obermaier Racing. Richard Lloyd Racing’s GTI Engineering would turn to Peter Stevens and Nigel Stroud to develop four 962C GTis, which featured entirely revised aero and aluminium honeycomb rather than sheet tubs. Former factory Porsche driver Vern Schuppan would also build five new chassis, some known as TS962s.