There have been a number of attempts at making a practical flying car over the years but none have ben successful: Hall Flying Car/ConVairCar, Hervey Travelplane, Waterman Aerobile, to name a few. I recall back in the fifties Hiller had an idea for a car/helicopter that used ducted fans in the fuselage instead of external rotors. It obviously never went anywhere - I don't know if they even produced a prototype.