The 1965 Grand Prix was based on an all-new 121-inch-wheelbase chassis, which again was shared with the Catalina. The body, while a completely new design, was instantly recognizable as a GP. The familiar stacked headlights, grille-mounted turn signals, concave rear window, and hidden taillights remained, but were interpreted in a new way.
The Coke-bottle sides were even more prominent on the new car, and a skeg ran from the bottom of the door through the rear quarter. The lines were truly striking. The headlight treatment was similar to the 1963 design, with an angular headlight bezel again cutting sharply into the front fender.
The new design was. also a bit larger and heavier than before. It gained an inch in wheelbase and 1 to 2 inches in all other dimensions. With the standard fender skirts, the car looked easily as big as a Bonneville sedan, which of course it wasn't.
The new GP, while very attractive and on the cutting edge of style, was not quite as sporty as it used to be. It was going the way of the T-Bird—that is, still offering the buyer performance combined with luxury, but not necessarily a performance image. The GP was becoming more mainstream, and it could now be ordered with a bench seat in place of the buckets and console. With cars like the GTO and 2+2 upholding Pontiac's performance image, it simply wasn't necessary to market the GP as a tire-shredder, although it certainly could be, if optioned correctly.