For the 1956 model, Ford made some changes. To give more trunk space, the spare wheel was mounted outside, Continental-style; the exhausts were moved to the ends of the bumper. Air vents were added behind the front wheels to improve cabin ventilation. To improve rear-quarter visibility with the removable hardtop in place, "porthole" windows were made available as a no-cost option. An optional 312 Y-block V8 was made available for those that wanted more performance.
1956 sales were 15,631, the lowest of all three 2-seater Thunderbird model years
For 1957, a more radical restyle was performed. The front bumper was reshaped, with heavier sides, "bullets" at the ends of the grille, and the section below the grille dropping down. The grille was larger. The tailfins were made larger, more pointed, and canted outward; larger round tail-lights were fitted. The spare wheel moved inside the trunk again, which had been redesigned to allow it to be mounted vertically and take up less space. The side "Thunderbird" script moved from the fins to the front fenders. The styling was so influential, the later British Anglia bore an uncanny resemblance to it. The Corsair was heavily influenced by the later "Bullet bird" of 1961-63.
Engine options increased, because Ford went racing with the Thunderbird that year. As well as the standard 292 and 312 engines, versions of the 312 were produced in higher states of tune, and even a few McCulloch supercharged versions, rated at 300 and 340 hp respectively.
1957 sales were 21,380, including three extra months of production because the 1958 models were late.
Source: Wikipedia
