Picture this. It’s 1955 and Mercedes is dominating the motorsport scene with the 300 Sport Light-Racing (SLR) race car, achieving a superb 1-2 finish at the Mille Miglia with legendary drivers Stirling Moss and Juan Manuel Fangio. How do you improve an already hugely successful machine? Set two of the W196S rolling chassis aside to begin work on a coupe version, complete with gullwing doors.

Then, disaster strikes. At the 24-hour Le Mans endurance race on June 11, 1955, a major crash kills 83 spectators as well as racing driver Pierre Bouillin and injures almost 180 people. Following the tragic incident, Mercedes decides to retire from motor racing. It wasn’t until 1989 when the three-pointed star returned to the world of motorsport.

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The 300 SLR Coupe was originally conceived to take part in the 1956 season, but with Mercedes withdrawing from racing, the project was ultimately axed. However, the two cars survived and one of them was used as a company car by none other than Head of the Test Department, Rudolf Uhlenhaut, hence the car’s name: 300 SLR Uhlenhaut Coupe.

Effectively a road-legal race car, the hardtop version of the 300 SLR used an enlarged engine derived from the W196 F1 car, so you can think of it as the 1950s Project One. The eight-cylinder mill received a bump in displacement from 2.5 to 3.0 liters and output was boosted to 302 horsepower (222 kilowatts).

At the time when it came out, the Uhlenhaut Coupe was arguably the fastest road car in the world, achieving a top speed of 180 mph (290 kph). Legend has it Uhlenhaut himself drove the namesake car on the German Autobahn from Munich to Stuttgart on his way to a meeting and completed the 137-mile trip in a little over an hour.

The attached video posted on YouTube by Mercedes-Benz Deutschland (hit CC for the English captions) talks about the uber-rare machine – believed to be the most valuable car in the world. While undisclosed, the car’s value does not really matter a great deal since Mercedes has no intentions of selling either of the two 300 SLR Uhlenhaut Coupes.

Video: Mercedes-Benz Deutschland / YouTube

Photos: Mercedes-Benz Public Archive

Gallery: 1956 Mercedes 300 SLR Uhlenhaut Coupe

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