Also for flying cars, when a non-flying car breaks down suddenly, it can be a dangerous situation but you just need to avoid hitting anything until your momentum is lost and generally have options (brakes might lose power assist but could work, if they don't there's still emergency brakes, and if those also fail, there's engine braking if you have transmission control, or steering back and fourth to lose momentum via turning friction, and once you're going slow enough, even colliding with something stationary can help).

With flying cars, maybe it can glide, assuming it even works like that and isn't more of a helicopter or just using some kind of thrusters. Plus, if you're falling to your death anyways, you might not have the presence of mind to try to optimize what you do hit with what control you do have to minimize damage to others. Hell, the safety feature might even be ejecting and leaving it to fall wherever, while hoping none of the other flying cars hit you or your parachute, or fly close enough to mess with the airflow in a way where the parachute might fail.

And that's not even going into how much more energy it takes to fly vs roll.

Flying cars don't make practical sense. And where they do, we already have helicopters.