1958 Ford Thunderbird. Despite the success of the Ford Thunderbird in its first three years, Ford thought that not enough people would buy the Thunderbird any more because of growing families in the U.S. Ford said that the only way that it would keep the ‘Bird was by making it into a four-seater, to appeal to the Baby Boom that was in full swing at the time. So, in 1958, the first of the four-seater ‘Birds rolled of the production line at Ford. This second generation of Thunderbird was dubbed the “Square Bird” because of its square roofline. Even though this change in design saved the T-Bird, the outside design did not last long. By 1960 the bird was redesigned to appeal to the younger crowd. And soon, the Thunderbird would find itself struggling for marketshare against another Ford mark: The Mustang. But that was to come.