Not every factory concept car makes it to the production line, but they all have a story. Here are five fascinating examples from the Ford Motor Company over the years. 

A fully operational working prototype built on a Lincoln production chassis, the 1953 Ford X-100 dream car, designed by Joe Oros, was originally badged as the Lincoln Continental 195X when it debuted in 1952. Advanced features included heated seats, integral hydraulic jacks, and experimental Firestone radial tires. The X-100 still exists today in the collection of the Henry Ford Museum.

The Mustang Milano, displayed at the 1970 Chicago Auto Show as a possible teaser for the 1971 production Mustang, employed a nearly horizontal fastback roofline with a functioning rear hatch. Paint was iridescent Ultra-Violet, while the trick tail lamp lenses glowed green when the Milano was accelerating, amber when coasting, and red under braking.

The driving force behind the 1955 La Tosca design exercise was the prolific Alex Tremulis, head of the Ford Advanced Styling Studio. In truth, no full-size version of the La Tosca was ever built—the car shown here is a one-third scale model disguised by clever photography. Tremulis and a co-worker devised a radio-control chassis for the model, and you can see the miniature La Tosca in action in this video feature at Mac’s Motor City Garage.

For the 1999 Tokyo Motor Show, Ford styling chief J Mays commissioned a concept vehicle from famed industrial designer Marc Newsom, creator of the Ikepod watch and the Embryo Chair. Named the 021c after the Pantone color for its bright orange paint, the compact Ghia-built sedan abounded in clever packaging features, including  a slide-out cargo compartment. The 021c still makes an occasional appearance in art musuem exhibits, though now the paint is a vibrant lime green.

With its Candy Gold paint and cab-forward driving position, the 1973 Explorer SUV pickup concept (also pictured at the Chicago Auto Show in the lead image above) looks at first glance like a knockoff of the Dodge Deora, the famed Alexander Brothers custom. But if you look closer you can see some key differences, including a fully functional pickup box and side-opening doors—far more practical than the Deora’s swing-out front hatch. Of course, the Explorer name was eventually applied to a production Ford SUV in 1991.