1) whether it is more efficient to have a car that hovers over a car that doesn’t.
2) whether they are as safe, or safer than the cars we have now.
3) if they can be made cheaply, and if someone can make money out of them.
If they’re less efficient than what we’ve got now, people won’t want to buy them because they’ll be expensive to run. Likewise, they won’t want to buy something that’s very dangerous. And they’ll never get made in the first place unless someone can make some money out of it (unfortunately, that’s the way the world works). In terms of the technology though, I’m sure it’s very possible!