Its noisy, its slow and the inventor seems to be living on another planet. He thinks this is the solution to cars. We should have these instead. It would be a deathtrap.
I would be more impressed if someone invented a car which ran on a new type of fuel, some people aren't safe to be on the road can you image the havok they could cause with one of these.
And as for flying 10 feet off the ground, so what, that wouldn't make a dramatic improvement as its not as if you could get a load of cars going over the same airspace since they can only fly at 10 ft.