The Aviation Traders ATL-98 Carvair was a Douglas DC-4 converted to carry 22 passengers and 5 front-loaded cars. The aircraft configuration was similar to the Boeing 747 (i.e. cockpit on an upper deck). The power came from four Pratt and Whitney R-2000 Twin Wasp radial engines.
The Carvair was used by Aer Lingus and British Air Ferries among others. British Air Ferries were the last operator in Europe of the aircraft, keeping them flying into the 1970s.