Oil

Running something like the flying car would need to take much more fuel than a car would, for it to fly it won’t be cheap to maintain, with the world near oil shortages in the future, creating a car with no new fuel methods that are commercially successful is not well planning for the future, and the flying car may just have to remain something taken from the future still.

Costs

Creating of something new will not be cheap, especially a flying car, making it fly, and all the other tings involved with the process will take billions to make, with a small demand of people who can afford the new incredibly high prices no one will want to develop the flying car.

Purpose

We can drive cars, they get us where we want to go, flying cars won’t be usable to travel to distant locations because of their engine capacities won’t be able to hold enough petrol. So there’s no point in having something worth billions and not get you very far. while you can buy multiple air planes, ships, land vehicles for a very small fraction of the billions.

Social Impact

Will the world accept flying cars, people who don’t have them will be disadvantaged, criminals will be able to afford them, and simply fly away from their crimes. Hit and runs will be much more easy, Would probably pollute the world by using more energy to run and enrivomentalists may promote the evils of the flying car. There will be no roads, which is good, but speed limits wouldn’t be applied and cause chaos in the sky.

Recession

No one will invest into something at this time anyway, people have made concepts but they won’t have enough to fund it so that the world can enjoy flying cars. The recession is just another little reason why the flying car will not be available for quite some time, if it ever gets invented into the real world for public purchase, it won’t be any time soon.