From an engineering perspective, racing cars are much closer to aircraft than they are to road cars; they just have their wings upside-down.
That's why fan cars can be considered cheating. The fan is made of mobile aerodynamic surfaces. The Brabham BT46B try to circumvent the rules by saying their fan was a cooling fan, it didn't work.
If you allow mobile aerodynamic surfaces, indeed, you are going to have aircraft. It is easy to imagine a car with actual wings, with flaps, ailerons and elevators.