 The long variant, termed the normal chassis with the radiator directly above the front axle, served as the backbone for the four-seater cabriolets, the 'B' (with four side windows) and 'C' (with two side windows), and for touring cars and saloons.The shorter chassis was for the two-seater cabriolet 'A', set up on a chassis on which radiator, engine, cockpit and all rearward modules were moved back from the front axle.The Sindelfingen factory employed 1,500 people to create the 540K, and allowed a great deal of owner customisation, meaning only 70 chassis were ever bodied by independent builders.