1962 Rambler (Budd) XR-400

In 1962 Budd made a prototype called Budd XR400 powered by a 270 hp V8 engine. However the design was rejected by AMC. The caption on 1-st photo (provided by Curt Hall) in Automotive Industries (July 1996) states: "The 1963 XR-400 prototype for Rambler provided extra passenger space behind the front seat. The fully operational XR-400 was a frequent feature in parades."

Source: www.shorey.net