It's fun to think about.  Most of the recent attempts I've seen are basically quadcopters anyways, so calling it a 'flying car' is a stretch.  I have to agree with Elon Musk on that one.  Until we have some revolution in propulsion and antigravity systems based on superconductors or nanotech, I think the concept of flying cars will remain a novelty for a very long time.  That doesn't even take into account that flying a copter is more difficult than flying a fixed wing aircraft. They would have to be completely autonomous for the average person to use.