Pontiac Phantom: Bill Mitchell’s Final Masterpiece

The Phenomenon - As we all know, one of the American giant automakers, General Motors (GM), has long been home to some of the greatest talents in automotive design. Among them stands Harley Earl, GM’s iconic Vice President of Design for over thirty years. Earl’s eye for potential helped shape GM’s golden age, and one of the brightest stars he spotted early on was William “Bill” Mitchell—a designer whose influence would eventually rival Earl’s own legacy.

The Pontiac Phantom (also called the General Motors Phantom and given the internal code name "Madame X") is a concept car created by General Motors (GM) in 1977. (Picture from: Dean'sGarage)

Bill Mitchell began his rise under Earl's mentorship and quickly made a name for himself, becoming Cadillac's first design chief in 1936. His bold, forward-thinking approach to design helped transform GM vehicles into rolling expressions of American power and elegance. By 1954, he was promoted to Director of Styling, and by the time Earl retired in 1958, Mitchell took the reins as GM’s Vice President of Design. Over the next two decades, Mitchell oversaw some of the most memorable cars in American history—from sleek Corvettes to stately Cadillacs and even the striking Buick Riviera.

The Pontiac Phantom posed along with its initiator William 'Bill' Mitchell, who hoped he could literally drive off into the sunset on his retirement day in the 1977. (Picture from: MyCarQuest)

But as Mitchell’s illustrious career neared its close in 1976, he had one final dream: to craft a personal farewell to the world of automotive design. He envisioned a concept car that would represent his style, legacy, and passion—a final creation that would capture everything he loved about car design. To bring this to life, he reached out to Bill Davis, a promising young designer who had collaborated with him on several projects before and earned his deep trust. Mitchell gave Davis creative freedom, stepping back from the drawing board and instead offering guidance as a patron. Together, they began work in secrecy, reopening Mitchell’s famously mysterious Studio X, tucked away in GM’s design building basement.

The Pontiac Phantom is designed by Bill Davis, a young designer who had worked with Mitchell on numerous projects. (Picture from: CarStyling.ru)

The project, initially nicknamed “Madam X,” was unique from the start. Mitchell gave Davis creative freedom, stepping back from the design process and instead offering guidance as a patron. Davis, along with a small team, worked quietly to develop the concept. The initial design was a notchback, but Mitchell—who preferred fastbacks—pushed for a change. The result was a dramatic, sculpted two-seat coupe, painted in a glossy double black finish that shimmered like ink. To accentuate its curves, a deep red color was used in the wheel wells, adding a theatrical flair.

The Pontiac Phantom is a fastback two-seat coupe built on the chassis of a Pontiac Grand Prix, featured the long bonnet of the V16 project cars, with the prominent prow flanked by rectangular headlights. (Picture from: Dean'sGarage)

When the full-scale model was unveiled, it was more than just a car—it was a moment. Under dramatic lighting, with professional models in elegant black gowns adding to the mystique, the concept stunned Mitchell and GM executives alike. Several divisions were contacted to explore taking the design further, and it was Pontiac that stepped up. They donated a Grand Prix chassis, giving the project a foundation. Even famed Italian design house Pininfarina was invited to bid on building the car.

The Pontiac Phantom has long, sweeping lines at the sides recalled both the classic 1930s cars and GM retro designs like the 1971-4 boat-tail Buick Riviera. (Picture from: Dean'sGarage)

Despite the excitement, the project quickly ran into trouble. The intricate body design made the costs skyrocket. Only the fiberglass shell was ever completed—there was no interior, no engine, and no working drivetrain. It was an art piece without function. Mitchell hoped to secure more funding to finish the build, but opposition from GM executive Howard Kerl—long at odds with Mitchell—halted any progress. The project was shelved, and the car, now dubbed the Pontiac Phantom, faced a grim future in storage.

The Pontiac Phantom only consists of a fiberglass shell, including not completed interior and does not have a drivetrain, rendering it inoperable. (Picture from: Dean'sGarage)

Like many GM concepts of the time, it was lined up for destruction. But a quiet rebellion among designers saved it. They managed to move the Phantom to the Sloan Museum in Flint, Michigan, where it remains preserved as a striking symbol of creativity that never got its chance on the road.

The Pontiac Phantom was primed with a special nitrocellulose black paint that had been used in the 1930s on GM luxury cars. (Picture from: Dean'sGarage)

Though Mitchell retired the following year without his dream car to drive home, his legacy was already secure. He had curated a personal collection of over 50 GM vehicles, ranging from production models to custom projects. Even in retirement, he stayed involved in design, opening his own consultancy before health issues finally brought his career to a close. He passed away in 1988, but his influence still echoes across the design language of American cars.

The Pontiac Phantom now sat on display at the Sloan Museum near Flint, Michigan after saved by a designer team from GM's crusher machine. (Picture from: Dean'sGarage)

For some, Mitchell’s crowning achievement was the Corvette—America’s sports car icon that he helped evolve into a true performance legend. Others point to his role in reshaping Cadillac, guiding the brand through decades of stylistic innovation and prestige. Both achievements reflect his deep influence across GM’s portfolio.

But many see his most enduring contribution in the rise of the personal luxury car, a category he helped define through bold proportions, refined details, and road presence that blended power with sophistication. The Pontiac Phantom may never have reached the production line or the highway, but as Mitchell’s final vision in sculpted form, it remains unforgettable—proof that true design can leave a lasting mark, even without ever being driven. *** [EKA [27092022] | FROM VARIOUS SOURCES | CURBSIDECLASSIC | CARSTYLING.RU | DEANSGARAGE | MYCARQUEST | WIKIPEDIA ]

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