The rolling resistance of a typical car is 0.01 to 0.015 [1], so the effective lift/drag ratio of a car's suspension is about 70 to 100, for just the wheels themselves. Missing from this number are the parasitic losses of all other unsprung mass, aerodynamic drag, and the costs incurred by traveling along roads which are neither level nor straight routes between your start and your end.
Small aircraft have L/D of 10-20 [2], and electric craft will probably fare slightly better if anything because of packaging advantages vs big ICEs.
I might do a more in depth analysis later and write up a Medium post, but my point is: Even just looking at the rolling resistance of the car and the whole L/D of aircraft, the difference is only an order of magnitude. Rolling resistance is one of the smallest contributions to drag in a car, so all up electric cars are probably only 3-6x more efficient than electric aircraft, and combustion cars are probably have a far smaller advantage.
[1]: https://en.wikipedia.org/wiki/Rolling_resistance#Rolling_res...
[2]: https://en.wikipedia.org/wiki/Lift-to-drag_ratio#Examples