The 500k is one of the rarest and most exquisite automobiles ever built by Mercedes-Benz, with examples often fetching more than $1,000,000 at auctions. This one, though, is even more special.

Built between 1934 and 1936, the Mercedes 500K carried the type W29 model designation. The K in its name highlighted its factory-installed and driver-activated Roots Kompressor (German for supercharger) that squeezed up to 180 hp from the vehicle’s straight-eight engine. Enough to take the ~2,700 kg (6,000 lb) model to a top speed of 160 km/h (100 mph).

Three different chassis and eight body styles were available for customers, with 342 units manufactured. However, only 29 examples of the 500K Special Roadster were built, and this particular model – with a rather controversial history – is one of them.

The car was tailored for German industrialist Hans Prym, but it disappeared in 1945, while he was serving a prison sentence handed to him by the Allies. Prym’s estate was used as a base for U.S. troops serving under General Maurice Rose at the beginning of the march into Germany, and the car “mysteriously” vanished during that time.

It’s believed that the American troops stole it, especially as it turned out in the USA almost a quarter of a century later. It was sold in 2011 for approximately $3.7 million to Dutch car enthusiast Frans van Haren, but in another twist of events, the car was seized by the German authorities when van Haren brought it to the Techno Classica car show in Essen, on account that the 500k Special Roadster belonged to the family of its first owner.

The Telegraph reports that in 2012, a court in Hamburg ruled that the US troops had no right to take the classic car and ordered that it should be returned to Prym’s heirs.

Now, the vehicle is once again offered for sale by Bonhams, under the rightful owners, and it’s expected to fetch between €5 million and €7 million ($5.5 million – $7.7 million) Talk about making a quick buck.

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