The appeal of the flying car is the idea of being able to take off and fly above traffic jams. But I've seen the Jetsons movie. George gets caught in mid-air gridlock every morning.
The sad truth is that flying cars would serve no real purpose. Sure, they'd be cool if only a few people had them, but if they became an everyday thing, they'd become pure hell. You'd have collisions that would end in death 90% of the time. Cars hitting each other, cars hitting buildings, ect.
Hover-cars and hover-boards would be nice if there existed some magical form of propulsion that didn't consist of either rockets that would burn holes in the pavement (not to mention fry nearby pedestrians) or pumping enough air to the ground to push a metal vehicle upward (which would simply blow away all nearby pedestrians).
I'm sorry folks, but all those crazy sci-fi modes of personal transportation we've been dreaming about since the early 20th century are all bunk. You want a jet pack? Prepare to have your legs and ass burned clean off, not to mention your newly dislocated shoulders and badly burned back.
You want a teleporter? Fine, which model do you prefer? The kind that fused Jeff Goldblum with a fly? The Star Trek variety that essentially evaporates you and places a clone in your destination (anyone else see the episode where a transporter accident created two Commander Rikers? Anyone? No? Just me, then)? Maybe you want the Stargate kind that sends your molecules from one device to another, but has the chance of splattering you against any object in front the exiting device, hmm? Oh, I know! Let's use the kind that folds the universe in half so your destination physically manifests next to you! I think not.