In addition, there was an attached Roots supercharger, which could either be engaged manually for short periods, or automatically when the accelerator was pushed fully to the floor.

The 540K had the same chassis layout as the 500K, but it was significantly lightened by replacing the girder-like frame of the 500K with oval-section tubes - an influence of the Silver Arrows racing campaign.

[6] As usual with Mercedes cars of this period the Sindelfingen factory provided in-house coach work, and employed 1,500 people to create the 540K, thus allowing for a great deal of owner customisation, meaning only 70 chassis were ever bodied by independent builders.

[7] With the outbreak of World War II in 1939, the proposed further boring-out of the engine to 5,800 cubic centimetres (5.8 L) for a 580K was aborted, probably after only one such car was made.

After the assassination attempt on Reinhard Heydrich in Prague at the end of May 1942, the Reich Chancellery would only use armoured cars for ministers and leaders of friendly powers.

[6] In 1956, the car was auctioned off by the US Army at the Aberdeen Proving Grounds in Maryland and sold to Jacques Tunick of Greenwich, Connecticut, with a high bid of $2167.

[10] In 1958, Tunick sold the car to the private collection of veterinarian Dr. George Bitgood Jr., who had it repainted in black and the chrome re-plated.

After Bitgood's death, the "Blue Goose" was shown by his family in June 2002 at the 101st Airborne Reunion at Fort Campbell, Kentucky.