1970 Porsche 917/10 Spyder prototype

Built as the prototype 917/10 Spyder and retained by the factory for an extensive development program encompassing wind-tunnel work, engine testing, and on-track evaluation at multiple circuits.

Acquired after a full factory rebuild; raced the car in various championships and later placed it in storage from the mid-1970s until 1997, then undertook a two-year restoration and demonstrated it at historic events from 2000 onward before selling in 2008.

Regularly demonstrated the car at various circuits and events including an appearance at Austria's Ennstal Classic with Gerhard Berger at the wheel.

Had the car exhibited at a concours event and subsequently commissioned a full restoration completed in late 2014, with the car refitted in Gulf Oil livery and a normally aspirated 5-litre flat-12 engine installed under the guidance of Jürgen Barth.

Car was fitted with a customer-specification nose section for this event after the October 1972 rebuild.

Car ran with the shovel nose for its first North American appearance; retired due to blown turbocharger.

Dropped back late in the race after running out of fuel.

First of a two-round South American visit organized at Interlagos; Kauhsen took victory in the opening contest.

Retired from the second round held one week after the first.

Wilson Fittipaldi participated in practice with this chassis but contested the race in the sister car 917/10-015.

Combined result across both Hockenheim Interserie contests gave Kauhsen 4th overall in the combined standings.

Car was entered by Bobby Rinzler; started strongly but failed to finish.

Fittipaldi qualified on pole but dropped back during a rain-affected race; the outing was intended as preparation for the German Grand Prix.

One of several historic demonstrations by Kauhsen from 2000 onward following the car's restoration.

Part of Kauhsen's series of post-restoration demonstrations from 2000 onward.

One of the North American historic appearances made by Kauhsen during the 2000s.

Part of Kauhsen's series of post-restoration demonstrations from 2000 onward.

Former Ferrari grand prix driver Berger drove the car at this Austrian event while it was owned by Dr Ulrich Schumacher.

Car was displayed and received the top award in the racing car category under its post-2012 ownership.

Complete chassis rebuild carried out by the factory prior to sale to Willi Kauhsen.

Two-year comprehensive restoration returning the car to its yellow and red Bosch livery, following approximately two decades in storage.

Work initiated by Willi Kauhsen; completed around 1999.

Full restoration completed in late 2014; car refinished in Gulf Oil colours and fitted with normally aspirated 5-litre flat-12 engine number 917-089, producing an estimated 630 bhp at 8,300 rpm, under the direction of former factory driver Jürgen Barth.

Car configured to replicate its 1971 Weissach wind-tunnel appearance, retaining the original tube frame and fitted with the Gulf-liveried Le Mans nose from the Rodriguez/Oliver #18 car.