While Porsche was unveiling the new Nürburgring-dominating 918 Spyder downstairs in Hall 3 here at the Frankfurt Messe , there was another Porsche supercar quietly and discretely on display upstairs in the same hall. That, of course, was the 959 . But not just any 959: this was the original Gruppe B prototype.The 959 was first developed as a rally car in the early 80s to compete with the likes of the original Audi Sport Quattro S1, Ford RS200 and Lancia Delta S4 . But Zuffenhausen soon saw its potential as a production road-going supercar , emerging as a technological marvel to challenge the decidedly linear approach of the Ferrari F40 . It still stands as a groundbreaking supercar in its own right, but also lead to the first all-wheel-drive 911 Turbo and set the stage for the Carrera GT and aforementioned 918 Spyder that followed to cap the top of the evolving Porsche range.This original Gruppe B prototype, which presaged the production 959, packed a 450-horsepower 2.8-liter twin-turbo flat-six into an even sleeker form than the final version that followed. We caught up with it on display as part of a display of 80s German classics, of which this 959 prototype immediately stood out as the pick of the proverbial litter. Check out the hotness in the high-resolution image gallery above.