What people usually mean when they talk about flying cars is something as small, safe, convenient and cheap as a ground car.

There will never be any such thing. The basic problem with the skycar idea -- the "Model T" airplane for the masses -- is that skycars have inherent and substantial safety hazards compared to ground transport. If a groundcar goes wrong, you only have its kinetic energy to worry about, and it has brakes to deal with that. It can still kill people, and it does, tens of thousands every year, but there are far more minor accidents that do lesser damage, and an unmeasurable number of incidents where someone has avoided trouble by safely bringing the car to a stop.

For a skycar in flight, there is no such thing as a fender-bender. It not only travels faster (it has to, for lift, or the fuel consumption for hovering goes through the roof, and there goes the cheapness), but has in addition the gravitational energy to get rid of when it goes wrong. From just 400 feet up, it will crash at at least 100mph.

When it crashes, it could crash on anything. Nobody is safe from skycars. When a groundcar crashes, the danger zone is confined to the immediate vicinity of the road.

Controlling an aircraft is also far more difficult than controlling a car, taking far more training, partly because the task is inherently more complicated, and partly because the risks of a mistake are so much greater.

Optimistically, I can't see the Moller skycars or anything like them ever being more than a niche within general aviation.