It may not be tip-top condition, but this one-of-a-kind 1954 Mercury XM 800 Concept that we found for sale on eBay is definitely a piece worth working on. Designed by John Najjar who was also responsible for the 1962 Mustang I Concept, the XM800 coupe prototype made its public debut at the 1954 Chicago Auto Show. The XM 800 then traveled the US auto show circuit through out the 1954 season. Although it was promoted by Ford as an “advanced design, engineered to go into volume production”, the XM 800 never passed the concept phase. -Continued In 1957 Ford gifted the XM 800 to the University of Michigan”s Automotive Engineering Lab for use in training “future” automotive engineers. According to the eBay seller, when the automotive school closed the car was sold to a private individual. After that the car was sold again to its current owner who has had the car for almost 30 years.