It is the most valuable car in the world, and in its heyday, it was the fastest road-legal car in existence. Only two were made, and despite its name and resemblance to both the 1952 W194 Le Mans race car and the iconic 1954 300 SL Gullwing it spawned, the 1955 300 SLR was not derived from either. Instead, the pair of road-legal 300 SLR coupés, known today as the Uhlenhaut Coupés, was based on the highly successful 2.5-litre straight-eight-engined Mercedes-Benz W196 Formula One car, with the power plant enlarged to 3.0 litres for sports car racing.
Prior to the Le Mans accident, Uhlenhaut ordered two of the nine W196 chassis built for modification into an SLR/SL hybrid. The resulting coupé featured a more sculpted body than the 300 SL fitted over a slightly widened SLR chassis with signature gull-wing doors. The cars were developed to race in the Carrera Panamericana, but the event was cancelled due to safety concerns following the 1955 Le Mans race disaster, which also led to the withdrawal of Mercedes-Benz from competitive motorsports at the end of that year.
With the hybrid programme abandoned, Uhlenhaut appropriated one of the mules as a company car with only a large muffler added to dampen its rorty exhaust noise. With a maximum speed of nearly 290 km/h, it was easily the fastest road car of the era, and legend has it that Uhlenhaut, running late for a meeting, roared up the autobahn from Munich to Stuttgart in just over an hour, a 220 km journey.
One Uhlenhaut Coupé is displayed at the Mercedes-Benz corporate museum in Bad Cannstatt. The other was sold from the museum in May 2022 to a private collector for 142 million USD – the highest price ever paid for a car –with the proceeds used to establish the Mercedes-Benz Fund.