Pontiac Grand Prix Model J
For 1969, John Z. DeLorean, Pontiac's general manager at the time, ordered the development of an all-new Grand Prix based on a slightly stretched version of the intermediate GM A platform, which was dubbed the G-body.
The previous platform was based on the 121 in (3,100 mm) wheelbase from the Catalina, but in 1969 it was decreased to 118 in (3,000 mm). This smaller, lighter car at last had its own body, and brought a new level style and luxury into the intermediate class. The redesigned radiator, "Coke bottle" body shape and other Duesenberg styling cues, plus Pontiac's longest-ever hood, gave the Grand Prix a feel of high luxury without the high cost. Unlike the previous generation for which a convertible was a one-year-only offering in 1967, the new Grand Prix would only be offered as a hardtop. Even the model names took elements of old Duesenbergs (J and SJ trim).
Source: Wikipedia, 2013