But now the flying car has at least been declared officially road legal.
It means the Terrafugia Transition could be in U.S. garages as early as next autumn, after two years of delays.
It may not be the world's first flying car, but its makers say it is the first to have wings that fold up automatically at the push of a button.
It costs $200,000 - about the same price as a Ferrari - and can be reserved online for what Terrafugia describes as a 'modest' $10,000 deposit.
The National Highway Traffic Safety Administration has officially announced the Transition, called a 'roadable aircraft' by its makers, can now be legally driven on America's roads.
It granted the vehicle special dispensations, which allow it to use airplane-style plastic windows instead of the safety glass usually used in cars, as it would be too heavy.
The polycarbonate windscreens can withstand the impact of birds, so they won't fracture.
The administration has also granted Terrafugia permission to use heavier-grade tyres, which are not normally allowed on multi-purpose vehicles.
It's the second hurdle the Transition had to overcome before it could go on sale, after the Federal Aviation Administration ruled last year it could fly with its current weight, 110lbs over the normal legal limit for light sport aircraft category.
Terrafugia had originally hoped to deliver its first production vehicles as early as this year, but after problems with suppliers it has had to delay the release date to late 2012.
According to Terrafugia, it 'combines the unique convenience of being able to fold its wings with the ability to drive on any surface road in a modern personal airplane platform.'
Prospective owners will need plenty of space for their new toy - it requires 1,700ft of road for take-off.
Its creators, which include former Nasa engineers, say the vehicle is easy to keep and run because it can fit into a normal domestic garage and uses regular gas.
It measures 19ft long and just 5ft 6ins wide when the wings are folded up, but they have a full span of 27ft.
It has a top speed of 65mph on the road, but that soars to 115mph in the air.
Drivers can convert it from a two-seater road car to a plane in less than 30 seconds with the touch of a button.
It doesn't have a gearstick, but on the road can be controlled with brake and accelerator pedals and a steering wheel like an ordinary car. In the air it is operated with a joystick near the steering wheel.
Well, the 2012ers will be holding their breath for the world to end or "transform", but apparently they might get stuck with flying cars instead.