I think it's closer than most of us seem to think. Teslas can already do it, autonomous driving was part of a recent software update. And I think @P Thought is absolutely right, there's going to be a paradigm shift. Car ownership will shift to hobby rather than requirement for getting around. There's this concept called "on-demand mobility," NASA is partnered with private industry to make it happen, and yeah, it includes flying cars when we can make those happen. But meanwhile, it applies to ground-based transportation, and Uber already has the concept of fleets of vehicles that you just page when you wanna go somewhere. The only difference between then and now is, A) Uber owns the vehicle, and B) there is no driver.