It is a counterpart to GM's Le Sabre concept, with which it shares many mechanical components, including its supercharged V8 engine, which could run on either gasoline or methanol.

The XP-300 is representative of GM's "long and low" design philosophy in the 1950s, and includes numerous innovative features ranging from push-button power windows and seats to hydraulic jacks and de Dion axles.

Together with the Le Sabre, the XP-300 pioneered the wraparound windshield, although it ultimately had much less influence on future car design than its counterpart.

Chayne had previously assisted Harley Earl in designing the 1938-39 Buick Y-Job, often regarded as the first concept car.

[1] Although somewhat similar in appearance to the Le Sabre, the XP-300's styling was noticeably cleaner than the more futuristic, rocket-inspired lines of its counterpart.

[6] Weighing in at 3,125 pounds (1,417 kg),[4] the total weight of the car was reduced by its use of heat-treated, aluminum body panels.

[8] It additionally features four coil springs and a hydraulic system more complex than that of the Le Sabre, which operates the car's cowl vents, door-locking devices, hood, jacks, seats, and windows.

[10][9] Similarly, a chrome fin runs through the center of the car's trunk, hiding hinges for the twin deck lids, while a floodlight-style, sealed-beam backup lamp was mounted in the central fixture, which imitates the exhaust of a jet engine.

[9] The interior of the XP-300 features pleated blue-leather bucket seats with adjustable inflatable air bladders and a center console.

[9] The car also has a telescoping steering wheel and an instrument panel displaying a prominently mounted combined speedometer/tachometer as well as a fuel gauge.

[6] During testing, Chayne claimed that the XP-300 achieved a top speed of 140 miles per hour (230 km/h) in the hands of Buick general manager Ivan Wiles.