Robin,

You know I worked in Longview/Kelso and have been to the Aero Car factory.

I met the guy that developed it. The Aero Car was part of a surge in ideas for the future that came about in the ten years following world war two.

His idea was a good one but the leap was too great.
To go to the expense of combining the plane with a car ignored the reality that most airstrips have cars within close enough proximity that the conversion wasn't necessary.

There was also the problem of FAA Certification for consumer use. The stresses a car faces are far
different than that of an airplane and it was obvious the airframe would quickly outlive the car if it were actually used as intended and with frequency.

Thus, a dream died and only the prototypes remain.
A neat bit of history.  I'm glad you reminded us of it.

Pat O'Day