In 1921 Edmund Rumpler wowed the Berlin Auto Show with the Teardrop. The engine components were enclosed in a tub underneath, and from the top it had a teardrop shape. The public thought it was ugly, it was hard to steer, there was no trunk space and it evidently was "outrageously expensive." Thinking it looked futuristic, Fritz Lang bought then at deep discount and blew them all up in his movie Metropolis.
In 1979, Volkswagen took one of the two remaining cars and put it in its wind tunnel. They found that it had a drag coefficent (CD value) of only 0.28, better than any car on the market at the time. Today it is still better than most of the cars on the market. ::Club of Pioneers
Rumpler front via Jalopnik
Make your own Rumpler! Slightly larger original here
The Toyota Prius beats it with a 0.26 CD, but interestingly, the lowest CD of any car produced since the Teardrop is the now-squished General Motors EV-1, with a CD of 0.195. The Aptera is projected to come in at 0.11, a new record. See a table of CDs at ::Wikipedia
See also ::Wheelspin
More on Aeromodding and Aerodynamic Cars in TreeHugger:
The Future is Here: Aptera's Prototype Unveiled
Wayback Machine 1933: "Aeromodding" a Model T :
DIY AeroCivic: It's Ugly, But it Gets 95 Miles Per Gallon
Why Do Cars Use So Much Fuel?
Car windows up & AC on versus windows down: which is more ...
Spy Shots: Honda's Upcoming Hybrid Looks Like... a Prius :