Video: listen to Audi’s top-secret Group S monster

When Audi entered rallying in 1980, it changed the game forever by bringing four-wheel drive to the party. Sending power to each corner gave a massive advantage on loose surface stages and snow. But by the time Group B was in full swing, Audi was actually under serious threat from its mid-engined rivals.

Even with the mighty flame-spitting S1, Peugeot’s 205 Turbo 16 and Lancia’s Delta S4 were both better balanced and more nimble than the Quattro, which, with its big five-cylinder up front, was a lot more susceptible to understeer. In response, they came up with something a bit special. It was called the Audi Group S Prototype. That’s it, in the video above.

The Group S prototype boasted 1000bhp from its mid-mounted engine, and was so secretive, Audi Sport developed it without the bosses back in Ingolstadt having any clue. In fact, the engineers took the project out of Germany to a facility in Desna in the Czech Republic, with the prototypes shipped in anonymous containers.

Rally god Walter Röhrl even had to do a test session on a public road (a track was booked but photographers got wind of the location) where, unsurprisingly, he got stopped by the police. Walter requested that they didn’t take pictures, which the police agreed to - but only if Walter would let them witness a proper race start.

Obviously, he obliged. Eventually, however, pictures of the secret prototype cars spread around the world and eventually onto the Audi bosses’ boardroom table. They weren’t very happy and demanded that all the cars were destroyed in front of them.

Which they were, apart from the car above that’s been hidden away in Audi’s secret shed for years. It recently came out into daylight and cleared its wastegates for a few runs at the Eifel Rallye Festival. You can check that rare glimpse above. And soak it up, because it's not likely to happen again anytime soon.