Might you be thinking of the Desoto Adventurer? It was a beautiful concept car in '54. Here's a link to some color and black and white shots of it :
http://www.shorey.net/Auto/American/DeSoto/htmltree.html
Page won't load... but this car is definitely 1960's. It's a slant six, and the pushbutton shifter is the same as a 1965 Valiant or Dart.