When you talk to most people about anarco-capitalism (new term:
Agorocracy), the first thing you most often hear is... "But what about the roads! We neeeed the government to put up stop signs and stuff! It'll be anarchy!"
Flying cars would go a very long way to reducing the need for government on a local level, except to enforce minimum altitude laws - a device on your property would transmit your rules for how low people can fly, with there being a special clause for emergency descents. There's so much room in the sky no one should ever be in a right-of-way conflict with anyone else, except when descending into a parking lot in densely populated area, but even then decentralized protocols can be easily worked out. (And new buildings will be able to utilize their roofs as additional parking space!) At cruising altitude, anyone trying to ram you will not be able to come within a mile of you without your radar catching him. You won't even need license plates because you can't just disappear from the sky, your insurance company would have the violator on their radar and track him until he lands. Etc.
Aspiring sci-fi writers, eat your hearts out!