Flying cars will always be a niche product
Although the Terrafugia represents a fresh approach to the challenge of building a "roadable aircraft", (I've seen the prototype close-up) flying cars will always be a niche product; of limited practical use and mainly a toy for the relatively wealthy. And since the potential marketplace is limited to hundreds-of-thousands of certified pilots and it costs a cool quarter-million, you won't be finding these in too many garages near you.
The unfortunate reality for any "flying car" is that too many of the requirements for a practical and desirable aircraft are diametrically opposed to the requirements for a practical and desirable automobile. Aircraft engines operate in a very different environment and duty cycle than auto engines. It's difficult to engineer one that is highly efficient for both. In aircraft, everything is about weight. In autos, less weight means a worse ride and safety. Due to their weight requirements, aircraft are notoriously fragile and vulnerable on the ground. When your car is in a fender-bender, you can either ignore it or get it repaired relatively inexpensively. If an airplane gets "bumped" in the wrong way, it means an expensive tear-down and inspection.
And then, there's the economics. Even in today's aviation, $250,000 dollars is an awful lot to pay for a plane that can barely fly 500 miles at 100mph, or a car that can barely travel on the highway.
I do hope that Terrafugia is successful, but it's with the hope that "success" is defined in hundreds of units built and sold, and not with the expectation of thousands.
