Waterman Arrowbile

This is a flying car, designed in the mid-thirties by Waldo Waterman.  It was developed from his first tailless aircraft; the Whatsit, which he worked on from 1911 to 1934. That design became the Arrowplane, which he entered in a government contest for a simple, affordable and easy-to-fly airplane. 
The success of that entry led to this Arrowbile, of which five were built and demonstrated successfully in 1937. Two actually flew from the Santa Monica factory to the Cleveland air races. Unfortunately, the public showed little interest and the project died. 
One remains on display at the National Air and Space Museum. 
More here on Youtube.