Here's a stunning piece of ID history: Back in the 1930s GM was working with chemical company Rohm & Haas on safety glass. As Rohm & Haas' manufacturing prowess with Plexiglas (which they had invented in 1933) became evident, a decision was made to skin a working car out of the stuff. According to RM Auctions,

Visitors to General Motors' "Highways and Horizons" pavilion at the 1939-40 New York World's Fair came away awed by a vision of the future. The work of renowned designer Norman Bel Geddes, GM's "Futurama" exhibit foretold the communities and transportation systems of 1960, many of which came to pass.... [Also on display] was the "'Glass' Car - The first full-sized transparent car ever made in America."

On the chassis of a 1939 Pontiac Deluxe Six...Rohm & Haas constructed an exact replica body using Plexiglas in place of the outer sheet-metal. The structural metal underneath was given a copper wash, and all hardware, including the dashboard, was chrome plated. Rubber moldings were made in white, as were the car's tires. It reportedly cost $25,000 to build—an astronomical figure in those days....

The car is [currently] in a remarkable state of preservation, a testament to the longevity of Plexiglas in an era when automotive plastics tended to self-destruct within a few years. Although it has acquired a few chips and cracks, it is structurally sound and cosmetically clear, showing off the Ghost Car's innards as it did in 1939. The car rides on its original U.S. Royal all-white tires and sports the correct white rubber running boards. From the beginning it was a running car, although extensive use would have been unduly detrimental. The odometer currently reads 86 miles. The only recent mechanical work has been replacement of the fuel lines.

The car was sold at auction for an undisclosed amount. We're guessing it was a damn sight more than $25,000.

via hemmings blog