This is a Mercedes-Benz 540K (Special Roadster Model). This is a car which was fabricated by the German firm Mercedes-Benz from 1935 to 1940. It was designed by Friedrich Geiger.

A factory in Sindelfingen, Germany employed about 1,500 people to create the 540K. Specifically, Sindelfingen is a German town near Stuttgart at the headwaters of the Schwippe (a tributary of the river Würm) that is the site for a Mercedes-Benz assembly plant. With the 540K, it allowed a great deal of owner customization, meaning only a limited number of chassis were ever used by 540K car builders.

Ultimately, the Mercedes-Benz company only built 406 of these exclusive automobiles. The exceptional combination of luxury and power was included in only 25 of the Special Roadsters. Cementing its importance in automobile culture, one of these cars was sold at auctions in London, England in 2007 for $8.2 million.

More Info: en.wikipedia.org