Fantasy fulfilled, you can check that one off the list now. :)
Via Al Fin comes notice of a practical, and - importantly - currently license-able for public by-ways use apparently, a flying car (OK, more of a dune buggy really). As Al Fin notes, the engineering requirements seem fairly modest to modify this for a pontoon arrangement of some sort and create a true all-surface accessible vehicle.
We're gettin' there fella's.