Sorry about bringing back this old topic. I was driving on the motorway this morning on my daily commute and, on a 20 miles stretch, hit the statinary traffic twice. One of those situations when the traffic stops for no obvious reasons: no road blocks, no accidents, just the sheer volume of traffic causing the wave effect.

Then I had the lightbulb moment and recalled this flying-cars topic. It is all fine and well to stop and wait on the motorway but how about flying cars? They need to maintain a certain minimum air speed or otherwise they would just drop off the sky.

It's lucky we don't have them yet

PS
I am aware that there are stationary flying solutions but those are even more energy hungry than the aerodynamic based ones. The fifth element is still far off.