Yet another restyled body kicked off the Thunderbird’s fourth three-year run in 1964. Beauty beneath the skin included the same unitized structure introduced in 1958 and a 300-horsepower 390 V-8 backed by a Cruise-O-Matic automatic transmission. Power steering and brakes also were standard, as they had been in 1963. The sexy Sports Roadster didn’t return but a dealer-installed tonneau cover was offered in 1964 to again help- revive two-seat memories.

Front disc brakes and sequential taillights became standard in 1965, and an optional 345-horse 428 cubic-inch FE-series V-8 appeared the following year. The sequential turn signals were incorporated within a new full-width taillight design in 1966, the last year for both the unit-body Thunderbird and its convertible rendition. Production was 92,465 in 1964, 74,972 in 1965, and 69,170 in 1966. Landau hardtops were offered in 1964 and 1965, a Special Landau hardtop appeared in 1965, and a Town hardtop and Town Landau debuted (both sans rear quarter glass) in 1966.