And even if they did succeed...
Right, ignoring the fact that every bit of footage I've ever seen of a Moller "craft" was either firmly on the ground and showing off its moving bits or wobbling erratically upwards a couple of feet while tethered to a crane "for insurance purposes/safety reasons", lets assume that, by some miracle, they get these things to work and address some of the hype:
They aim to create affordable (to the average citizen) flying cars that will alleviate traffic conjestion by creating successively larger layers in which to travel.
The average citizen.
Are they effing nuts? If these things worked, they would be AIRCRAFT and require a trained pilot, not the average dickheaded citizen that runs motorcycles, other cars, vans and even full-sized buses off the road and says "sorry, mate, I didn't see ya". FFS, the average consumer can't spot hazards (other vehicles, pedestrians, buildings etc) in the largely 2-dimensional environment of the roads, let alone in three dimensions!
But, argues Moller, the vehicles would be totally computer controlled and guided by GPS so the average citizen would merely be a passenger, they'ed get in, enter the destination and the flying car would deliver them to their destination. I'm sure I even saw some crap about the possibility that you could ease parking woes by sending it home on autopilot and call it to come and pick you up later.
Well, GPS units guiding drivers into public toilets aside and ignoring the inherent waste in having your aircraft fly you to work, fly home, fly back to work, drop you at the pub, fly home, fly to whatever brothel you managed to crawl to in a drunken stupor and then fly you home again, these things are still (hypothetical, highly conjectural, pie-in-the-sky) AIRCRAFT and would require a human operator to perform an in depth pre-flight check and (honestly) deem the craft fit for takeoff and would have to routinely undergo rigorous airworthiness tests as required of planes and helicopters.
Like the average citizen of today diligently checks lights, tyres, brakes etc etc every time they use their vehicle and always ensures their current vehicles are strictly up to warrant of fitness standard and never drives knowing a tail light is out or with an expired warrant of fitness.
Enough accidents are caused by bald tyres, shitty brakes, buggered steering, stuffed wheel bearings or brake lights failing to activate and warn the (tailgating idiot) driver behind, without putting the average citizen in charge of maintaining (or paying for the maintenance of) a complicated aircraft that is likely to fall out of the sky due to faulty bearings in the turbines.
And of course, the whole "running out of gas" on the way to work is going to have dire consequences - the damned thing may well be programmed to make for the nearest service station once it hits a certain level of fuel but as the old proverb goes: "you can lead a dickhead to a service station but you can't make him fill the tank."
The cost in fuel has already been covered so I won't go into that here (and for all we know, they might discover a way to make eco-friendly flying car fuel using harmonious energies from amethyst crystals to irradiate organically-grown mung beans - like, WOW!)
Aerodynes/Ducted Fan Vehicles/Vectored Thrust Vehicles/Personal VTOLs are grist for the mill in any good SF or Cyberpunk story and I'd like to see someone come up with a viable, usable design but I would not expect to (nor want to) see it in the hands of the average citizen.
As aircraft, they would be expensive and limited to military, police, rescue services, commercial transport and a few personal craft owned by the extremely rich - pretty much as fixed wing and gyro aircraft are today.