They meant flying cars that are efficient, quiet and affordable.
But that will always be dumb. Basic physics is against you there, and flying will always cost more energy than driving. Spending more energy will always more expensive than spending less energy. Spending more energy will mean more energy "leaks" in the form of noise.
The laws of physics dictate that flying will be expensive and noisy, compared to rolling. And that's completely ignoring things like the very simple fact that a rolling car that breaks down will roll to stop, a flying car will stop flying (and crash).
That’s what “flying cars” alludes to, and it’s a long way from a society where people have to be warned not to eat a sandwich wrapper.
A fictional thing that stupid if you think about it for more than 30 seconds?