The car was a collaboration between Harley Earl and Charles Chayne. After working together on the Buick Y-Job, their imaginations soon produced other imaginative Buick concept cars. In 1951, the pair created two new dream cars, The Buick LeSabre and XP-300. These vehicles were the result of a long-term cooperative venture between GM Styling and Buick Engineering. LeSabre was Harley Earl's project while Charles Chayne (then the head of GM Engineering) took the lead on XP-300.
The two cars had many mechanical components in common, including the supercharged 335hp V8 engines that burned a fuel mixture of methanol and gasoline, push-button seats and windows (including convertible rear windows) and hydraulic power jacks that were operated from the driver's seat.
While the two cars shared similar underpinnings, the styling of their aluminum bodies clearly distinguished the LeSabre and the XP-300. The XP-300 has the clean design of a sports car and the dramatically sculptured LeSabre has the look of a jet plane. LeSabre's styling cues clearly suggest its namesake, the F86-Sabre jet fighter.
The exterior of the car is typical of the 'long and low' style that many GM stylist tried to promote during the 1950s. At over 16 feet in length, the XP-300 has only 6 and 1/2 inches of ground clearance. The body panes are made of heat-treated aluminum, which reduces the overall weight of the car to 3,100 pounds. The body and frame structure are welded into a solid unit. Wide brake drums allow for a double set of brake shoes.