The second generation Ford Thunderbird (also called Square Bird) was produced by Ford for the 1958 to 1960 model years as a successor to the popular 1955–1957 two-seater. In response to Ford-conducted surveys two major changes were made to attract potential buyers: two rear seats were added and the level of luxury and features of a full-sized car were incorporated into a mid-size platform. Along with the 1958 Lincolns, the 1958 Thunderbird was the first Ford Motor Company vehicle designed with unibody construction.