It's hard to imagine an even wilder, more hardcore rally series than Group B, but that's exactly the world for which Audi's rarely seen "RS 002" was developed.
Audi's Sport Quattro was a dominant force in the Group B rally series during the '80s, and a highly successful publicity machine, because it looked (somewhat) like the Quattro you could buy at an Audi dealership.
But as Group B started to reach its climax, several brands started exploring a new series, to be called Group S, that would supersede Group B. Audi, of course, was one of these brands and started work on a new contender that would be entirely purpose-built for rallying, and not constrained by using the base of a production model.
The result from Ingolstadt was this white monstrosity, a mid-engined, spaceframe supercar with plastic bodywork and a heavily revised 20-valve version of the marque's 2.1L 5-cylinder engine pumping out 515kW! The car weighed 1000kg and had a top speed of 300kph.
The car was completed and tested by Walter Röhrl, but then a number of tragedies struck Group B, and the FIA decided to cancel Group S, too.
Since then the Audi Group S prototype has been rarely seen, but in recent years Audi has given the priceless machine a few runs at classic car events. Check out the video below to hear it scream (and crackle).