Only way this is ever going to work is by starting with everyone going for a ride in the brain boost machine from Forbidden Planet. THEN we might be able to have a chance at surviving flying cars.
The level of skill required to drive a car is abysmal - take a look at the results from driving standard 2D surface vehicles. Mostly, 2D drivers only need to have a pulse (although that might be optional) and be able to find their car keys.
Flying an airplane in 3D takes a LOT more skill and care than driving a car. 99% of the w*nkers on the road today wouldn't survive the first two minutes in a flying car or even a conventional airplane. It is utterly beyond their "skill" and concentration level. It requires 50 to 60 hours of training just to earn a basic private pilot license, and that's for simple aircraft in good weather. It takes another 200 hour or so before you're really any good at it.
For flying cars to be possible, it will be necessary to take the driver out of the loop almost completely. The entire input from the driver should be to tell the vehicle the destination. After that, autonomous systems would have to start the engine(s), aviate and navigate, and land at the destination. I see multiple, redundant computers, some on-board to operate the systems, and some centralized to handle traffic flows, route around obstacles and weather, etc.
Unless we want to pave the entire world with landing strips, the vehicle needs to have vertical takeoff and landing capability. Additionally, if the cruise speed isn't significantly higher than standard ground vehicles, the whole thing is a waste of time. So we need a mostly automatic vehicle, connected to a complex central command and control infrastructure, and the vehicle needs to be able to take off and land vertically, then transition to a cruise speed of say 250 mph (The V-22 Osprey - and its painful teething problems - comes to mind), and be able to do so for at least three to four hours, when loaded totally haphazardly by someone who has absolutely no idea what they are about . . . and did I mention that this vehicle is going to need quite a bit more attention and maintenance than is "lavished" on the average car? ("If it starts, its OK to drive!")
And it has to be green, too.
Sorry, guys, ain't gonna happen. (Someone please prove me wrong, but I'm not holding my breath.)