An innovative model was introduced on February 4, 1964. Using the new GM A platform (RWD) the Sport Wagon used a 120-inch (3,048 mm) wheelbase, that was 5 inches (127 mm) longer than the other Skylark four-door sedans and wagons. The 1964 to 1967 Sport Wagons had a Skyroof that consisted of four tinted glass panels surrounding the elevated section of the roof. A forward-facing third row of seats was optional. Sport Wagons were available in standard and more upscale "Custom" trim package.