Overall length of the Mustang and Falcon was identical, although the Mustang's wheelbase was slightly shorter. With an overall width of 68.2 in (1732 mm), it was 2.4 in (61 mm) narrower, yet the wheel track was nearly identical. Shipping weight, about 2570 lb (1170 kg) with the six-cylinder engine, was also similar. A fully-equipped V8 model weighed about 3000 lb (1360 kg). Though most of the mechanical parts were taken directly from the Falcon, the Mustang's body shell was completely different; sporting a shorter wheelbase, wider track, lower seating position, and overall height. An industry first, the "torque box" was an innovative structural system that greatly stiffened the Mustang's construction and helped contribute to better handling.
The 1966 Mustang debuted with moderate trim changes including a new grille, side ornamentation, wheel covers, and gas cap. Additionally an automatic transmission for the "Hi-Po," a large number of new paint and interior color options, an AM/eight-track sound system, and one of the first AM/FM monaural automobile radios were offered. The 1966 Mustang did away with the Falcon instrument cluster and made the previously option-only round gauges and padded sun visors standard equipment.
The 1968 Mustang fastback gained pop culture status when it was used to great effect in the crime thriller Bullitt. Lt. Frank Bullitt, played by legendary actor Steve McQueen, drove a modified Mustang GT-390 fastback, chasing two hitmen in a Dodge Charger in the film's famous car chase through the streets of San Francisco.Source: Wikipedia.