Five of these cars were built, three of which are known to survive today. The first example was built for Nazi Herman Goering; it was the only one built to bulletproof standards. At the same time, Mercedes-Benz was building a 540K Special Roadster for Goering. When both cars were completed, Goering chose the Mercedes-Benz, primarily because it featured bulletproof doors and door glass, while the Horch featured only a bulletproof windshield. http://www.rmauctions.com/Restorations/Awards.cfm?CarID=37&AwardID=&fc=0#