1955 Mercedes-Benz 300 SLR Uhlenhaut Coupé  Mercedes-Benz. Only 59 cars have ever sold for more than $10 million (nominal) at public auction. Although the most expensive car ever is the 1955 Mercedes-Benz 300 SLR Uhlenhaut Coupé, Ferrari is the most expensive car marque with the 250 models especially highly-priced.