1956 Buick Series 60 Riviera Sedan (top) and Cadillac Sedan de Ville, There is no denying that the hardtop body style was a triumph of midcentury auto design. Depending on who you ask, the 1949 Buick Roadmaster Riviera coupe was the first regular-production hardtop of the post-war era. For General Motors, things got even more […]