This is going to be a major issue for flying cars for a long time, as they may be limited to mostly ground use for quite a while. The dream of just pulling one out of your garage and flying to your office is a long way off, as it will be quite a while before an effective system of managing tens of thousands (or more) of them flying low over cities during commute hour is in place.
Given this, a flying car that can only fly and not drive on the road will be nearly useless except in very niche circumstances. These hybrid ones that can both fly and drive on the road will probably improve over time, but why pay such a large price for one when it will be used mostly on the road and has very limited flying range.