The first, full-scale Levacar, the newest development in wheel-less, air-propelled vehicles, was introduced today by Ford Motor Company at the Rotunda in Dearborn, Mich. Compressed air, emitted through small holes in three levapads on the under side of the vehicle, provides a friction-less ride in which the Levacar slides on a film of air a fraction of an inch above the surface. Electric controls enable the driver to levitate, start and stop the…