1938 Mercedes Benz 540 K Roadster Auction: Bonhams, The Mercedes Benz Sale in Stuttgart, Germany. 19 March 2016. NOT SOLD: Highest Bid €2,200,000 © Bonhams Home » European » 2016 Bonhams Mercedes Benz Stuttgart Sale (Auction Preview) » 1938 Mercedes Benz 540 K Roadster