Another comparison with the Volkhart-Sagitta. I was watching a video on industrial design, and he mentioned that the Convair Model 118 would do 90mph on the road, with a 26 HP Crosley engine.
vintagenewsdaily.com/historical-photos-of-convair-model-118-convaircar-a-prototype-flying-car-of-which-only-2-were-built-in-1947/
Similar performance for a 4-passenger car with a rear 4-cylinder engine. Forget the flying-car-death-trap part.