I can see no way to prevent cars becoming airborne in an open wheeled formula.
Car bottom designs that allow aerodynamic lift at low angles of attack should be avoided of course but once initialy airborne the shape of the car has little influence on how high it flies as by that time the airflow will be broken up and the surfaces stalled.
It is wheel contact and riding up that causes most flips and unless a more closed wheel design is used there is no cure.