With the restoration of the 1956 Mercury XM-Turnpike Cruiser, Tom Maruska has now pulled three of Ford's show and concept cars from the brink of oblivion, preserving not just the cars themselves and the work of many talented designers and craftsmen, but also the sense of wonder and awe that the cars were intended to inspire. Show car restorations are rare, in part because show cars in need of restoration are rare, but mostly because it takes a special kind of restorer willing to go beyond the catalog parts and NOS stockpiles and find truly one-off parts, or source materials forgotten to most supply houses, or fabricate a part that nobody will ever see again for the sake of pure authenticity.

Rare, yes, but far from nonexistent.

While most show and concept cars remain within the clutches of carmakers' collections and museums, many have still made it out to the general public, either due to that security guard who happened to look the other way for the design honcho or due to the carmakers' occasional housecleanings at public auction. Whether hidden away in some dark catacomb under Dearborn, Michigan, or left out to the elements like the XM-Turnpike Cruiser, time still takes its toll on these show and concept cars. We can think of plenty we'd like to see located then given the Maruska treatment.

For instance, we know at least one of the GM Futurliners, Peter Pan's spare bus (No. 11), sits exposed to the elements just off a highway in Springfield, Massachusetts. There's probably just enough left of it—and just enough combined experience from the two or three recent Futurliner restorations—to make such a restoration possible.

Alternatively, there's evidence to suggest that one or two 1955 Chrysler Falcons might have made their way into the wild. If so, they're likely not nice and clean and shiny, sitting in somebody's collection; rather, they're likely deteriorating under a cover in a long-forgotten warehouse, waiting for somebody to uncover them and restore them to turntable glory.

Providing the carmakers or some philistine storage space landlord never crushed them, here's a bevy of show, concept, and prototype vehicles nobody's seen or heard about in decades, like the GMC L'Universelle at the top of this story, the GM Bison, the Ford Mystere, the Cadillac Interceptor, that weird Gremlin/AMX/Rambler thing... the list goes on.

Which show or concept car that was actually built (and not merely rendered) would you like to see tracked down and restored? Or, even better, which show or concept car have you tracked down and restored or are in the process of restoring? Let us know in the comments below.