Once the Group B era of the World Rally Championship reached its height in the mid-1980s, a group of manufacturers broke off to create a new generation of cars, dubbed Group S. Audi was one of those upstarts, creating a mid-engined car with a spaceframe chassis, plastic bodywork and a 20-valve version of the Quattro five-cylinder engine. Fatal crashes in '87 led to the dissolution of both groups, but this lone Audi Group S Prototype was hidden away and survived detection for years. Its design, made for a series that was scrapped even before it started, features 1000bhp from its mid-mounted engine. Last month, it was brought out of hibernation and run in public for the very first time at the Eifel Rallye Festival in Germany. See it in action below.