The bureaucratic issue is not the one I was thinking of (though it's also a serious concern). The problem that "flying cars" are supposed to solve is taking traffic out of everyday commuting by replacing it with flight. But unless your home and office are both right next to airfields, roadable aircraft aren't going to do anything about that, and in every case so far, roadable aircraft have been poor aircraft and poor automobiles.
Addressing the problem that humans really want solved--flight from driveway to downtown--will require:
1) Some sort of helicopter.
2) Fully computerized operation.
3) Infrastructure to support this mode of travel (eg helipads in the city).
4) FAA regs that permit it all.
Roadable aircraft are an interesting engineering exercise but they don't address any actual problems that I'm aware of. Drones, on the other hand, do present a possible path to flying-car utopia. It's easy to see automated drone operation progressing to the point where they'd be reliable enough for man-rated operation, and they're forcing changes at the FAA to accommodate them.