When we will be having flying cars any skyways like in Back to The Future?

I think there is only a few ways to achieve that. First is we can discover anti-material which is not affected by gravity force. Or we found a new source of energy which could sustain cars weight in the air long enough. Or we can improve our current magnetic field technology to cover wider area. But i think it won't be so soon. Science & Technology are usually triggered by needs like tactical warfare, space race, cold war, economical requirement & so forth. Since the need for flying cars is not in dire need yet, and it could be messy if all the cars flying around, so there is not much push for this kind of technology yet. Beside, our gasoline fuel is going to deplete soon (may be by this century) so people are looking for substitude of energy source instead of look for flying cars.