Mercedes-Benz 540k special roadster Dating back to an era when style was as important as function, and there was no such thing as “over-engineered,” the 1936 Mercedes-Benz 540k Special Roadster was likely the pinnacle of pre-war European automotive engineering. Built in coupe, cabriolet and armored limousine models, the topless variants are among the most desirable. Currently owned by car collector and upscale catalog retailer.