Ford Nucleon Concept
The Ford Nucleon was a scale model concept car developed by Ford Motor Company in 1958 as a design on how a nuclear-powered car might look. The design did not include an internal-combustion engine, rather, the vehicle was to be powered by a small nuclear reactor in the rear of the vehicle, based on the assumption that this would one day be possible based on shrinking sizes. The car was to use a steam engine powered by uranium fission similar to how nuclear submarines work.
The mock-up of the car can be viewed at the Henry Ford Museum in Dearborn, Michigan.
Source: Wikipedia, 2011