I was just watching Top Gear and they had a VW GTI W12-650 concept car that actually worked. However the braking system didn’t function that well, it had no air-con, but the design is awesome I think.

No Golf has ever been more powerful, or wider, or faster. The GTI W12-650 gives the appearance of having come directly from the racetrack. A Golf that could be the pace car for the 24 hour race at Le Mans. Its name is its mission: W12 cylinders, 650 PS (477 kW at 6,000 rpm). A showcar, no more, no less. At the same time it demonstrates the enormous potential that such a car can offer. - Source

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