If part of the appeal of buying antique cars is owning something unique that no one else has, then the person who just purchase a 1939 Pontiac Deluxe Six "Ghost Car" is certainly happy today.

The transparent car, made out of Plexiglass for the 1939/1940 World's Fair in New York, sold this weekend for $308,000. The auctioneers, RM Auctions in Michigan, say it's the only one to exist, but there are some reports that there may be one more out there.

While a lot of things at the World's Fair showed where manufacturers imagined the future was headed, no one really thought we'd all be driving around in naked cars. The body was molded by Rohm & Hass, the inventor of Plexiglass, to show off the revolutionary new material.

This Pontiac is unrestored, so there's some visible damage that's been accumulated over the years, but this impressive artifact is the first full-size automobile rendered see-through and therefore deserves a place of prominence in someone's collection ... or living room. Either way, it will be a conversation piece.

Although unique, the car did not come anywhere close to breaking auction price records. Last year, a 1956 Bugatti Type 57SC Atlantic sold at an auction in California for over $30 million.

See below for more photos.

Contributing: Dan Roth, Autoblog