1956X Buick Century Experimental Car Was Bill Mitchell's Ride; Hides Awesome V8 Surprise

Bill Mitchell is a name that needs no introduction to gearheads with an appetite for real cars, automobiles with personality, character, flare, tenure, elegance, comfort, power, and style – all at the same time. Just like his mentor, the legendary Harley Earl, Bill had a soft spot for Buicks, thanks to his old man, who was a dealer for the GM brand.

As the head of the design department for Buick Motor Division and later General Motors Corporation, Bill Mitchel made a habit of customizing unique versions of a production vehicle for his personal use. In 1956, a Buick Century Convertible was modified to his taste – 225 modifications in total. Most of them are hidden under the hood or aren’t immediately apparent, but this car is probably the most extravagant Buick ever made, topping even the Y-Job of Harley Earl, the first concept car in the world.

Mitchell liked the chassis of his cars to be painted red, and this 1956X Century Buick obliges. But that’s just invisible frippery; look at those front swivel seats. Eight-way power seats that have electric motors for everything, including the headrests. The two bucket seats in the rear also feature this ultra-cool design gimmick – the cushions periscope up with a flick of a button.

The headrests’ movement is controlled by individual switches for each occupant – the driver had five buttons at his disposal – one for each window and the fifth for raising and lowering the headrest. After Mitchell no longer used the car, Buick sold it – without the power seats and console. About the innovative seats: the driver’s could turn outward 90 degrees (for easier entry and egress), but the front passenger could swivel 180 degrees and face the other road companions.

William Mitchell had 55 different cars custom built for himself by GM styling, most of them painted blue, with red chassis, chromed pedals, and a tachometer - either on the hood or dash. This 1956X (X is for ‘eXperimental’) rev-meter dial is on top of the dash, in the foam padding, and no other Buick from that year is known to feature one.

Another unique trait of the ‘Mitchell Buick X’ is the rocker panel dual exhaust, a subtle hint at WWII warplanes –like the double gunsights at the far end of the front fenders. In the Buick lineup of 1956, Roadmasters were the only models to sport fender-top ornaments. This custom Century convertible has 1955 Roadmaster-style decorations clad in chrome.

Mitchell had a sweet tooth for the shiny plating on his cars (his private ones even more so than those he designed). The two-tone paint shade separator trim piece on this 1956X is made of brass – GM stylists preferred this metal because it was the easiest to work with for one-off projects that didn’t advance into series production.

The driving lamps installed in the front bumper "bombs" and the tail lamp lenses (custom clear units with red reflectors) are other details not found on any other Buick of the era. And, when Mitchell opened the doors of the 1956X Century in a low-lit space, the rectangular lamp under the car illuminated the ground.

After the car was sold (for $195 and a trade-in in 1963), it spent several decades in the possession of the first ‘regular’ customer until 1995. An avid car nut bought it (four years after it first read the sale ad in the Buick Bugle). Funny enough, the man carried the ad cutaway in his wallet from 1991 to 1995, and when he found it, he called the number. The car was still for sale.

The car laid dormant for the next 15 years, awaiting a restoration that finally debuted in September 2010. Every spring, fall, and winter Tuesday of the following 100 months (until February 2019), a group of non-paid volunteers (most retired auto workers) gathered in the owner’s garage and worked on the car. The team of 16 devotees put their mastery and energy into recreating the vehicle to its original specifications.

Some tasks required serious investigative work in the GM archives, but a stroke of luck resolved others. The Buick boasts seven shades of blue – two on the outside and five on the interior. Since the original paint wore the battle scars of half a decade of ownership when the restoration began, the volunteers were in a tight spot. Luckily, upon disassembling the rear bumper, they found an area hidden from sunlight and still had the original colors. It was from that secluded spot that the exterior livery was then replicated.

Except for the seats, the interior was mostly intact with the original upholstery door panels, trim, bolt-on carpet, floor grilles, chrome pedals, padded dash, and custom steering wheel. The seats were a detective’s work since there were no detailed documents about them. After meticulous research and several meetings with the GM styling department, the restorers got a breakthrough and could reproduce the original pieces.

Highly unusual for the era, the 1956X Buick features two side mirrors glued to the vent windows behind the wraparound windshield. But this Buick isn’t just a looker – the fashionable hood hides a jaw-dropping surprise. 322 cubic inches of Nailhead V8 (5.3 liters) area neatly tucked under the unusual intake manifold.

Four Carted one-barrel carburetors sit at the extremities, something Mitchell probably borrowed from the Corvette. The Corvair would use a similar side-draft setup due to its unique horizontally opposed six-piston powerplant architecture. Apart from the radically different intake, the V8 is the standard Buick engine for 1956, with 255 horses and 341 lb-ft of torque (258 PS, 462 Nm), coupled with the automatic Dynaflow transmission.

According to the current owner of the car – who bought it in 2019, just after it was restored – only two other GM V8s were made with this particular intake setup. Critically, the V8 is very nice to drive, and the man who now curates this Buick is an avid collector of rare General Motors machines. Steve Plunkett is well known for his collection of Cadillacs (more than half of the 91-piece collection) and has an affinity for extraordinary cars. The 1956X Century would fit the bill, and you can play the video below, shot by Lou Costabile in January, to see the car on the road.