The history of General Motors is one filled with countless hits and misses. There are so many of them that we even have a series dedicated to documenting each one. Some of GM’s misses could have been hits had the manufacturer been willing to give these models a chance. One of them was a mid-1960s project at Pontiac to deliver an affordable sports car for the American enthusiast. The 1964 Pontiac Banshee was supposed to be a Ford Mustang and European import killer, but GM clipped its wings before it could even achieve greatness. Now, you can own the only 1964 Pontiac Banshee XP-833 hardtop, the experimental car for a future that could have been.
Some readers have voiced concerns that our recent Holy Grail nominations have ventured too far from the roots of this series. Keep in mind that our version of Holy Grail is loosely based on the joke of David Tracy continuously finding rare Jeeps with manual transmissions. So, we’ve never really followed the definition of “Holy Grail” in the traditional sense. This series is dedicated to highlighting the best, weirdest, rarest, or most bombastic versions of vehicles throughout history. They can be anything from an outrageously expensive piece of motorcycle art from Honda, or the coolest version of the once-common Mercury Tracer.
My goal is to provide you with a comprehensive retrospective of awesome vehicles that deserve your attention. The Holy Grail moniker may not be literal, but the vehicles are great.
This story takes us back to the early 1960s, when gas was cheap and Americans were becoming a bit obsessed with sports cars. Hot Rod magazine sets the stage by explaining what was going on back then. In 1960, Chrysler hinted at sports cars with the reveal of the Plymouth XNR concept. Two years later, Ford also toyed with a sports car concept with the mid-engine V4-powered Ford Mustang I. Automotive legend Carroll Shelby was also fitting Ford V8s into curvy roadsters from Britain, and those cars went on to stomp the competition. The Chevrolet Corvette enjoyed a cushy position as America’s sports car, but maybe it would have some challengers to the throne.
The country was running a sports car fever above 100.4 degrees and Pontiac wanted in on the action. What its engineers produced could have been an icon if it were allowed to shine.
The Two-Seat Sports Car Dream
One of the best sources for history on the 1964 Pontiac Banshee XP-833 appears to be Hot Rod magazine as journalist Steve Magnante got to speak to Bill Collins, the engineer working under the wing of John Z. DeLorean to turn the dream of a Pontiac sports car into a reality.
As the magazine writes, Collins arrived at Pontiac in 1958. DeLorean arrived at the marque only two years prior under chief engineer Pete Estes and general manager Semon “Bunkie” Knudsen. DeLorean’s job was to add spice to a brand some thought was becoming bland. It didn’t take long for the brand to revamp its image. 1959 was the debut year for Pontiac’s Wide-Track, a design trend that added 5 inches of width to the front track and 4.5 inches to the rear track of Pontiac’s cars. Pontiac’s cars suddenly looked low and oh so wide, plus, Wide-Track also helped with stability. Advertisements showed almost comically wide cars and the public ate it up.
By 1961, DeLorean landed into the position of Pontiac’s chief engineer. DeLorean and his team’s next hit came in 1963 when they cut through GM’s ban on auto racing and limitations on big engines in intermediate cars. They found a loophole that allowed intermediate cars to have large engines as an option, and they fit a LeMans with a 389 cubic inch V8, creating the Gran Turismo Omologato. This was the car that for many, made John DeLorean an automotive icon. Pontiac sold 32,405 LeMans GTOs in the 1964 model year.
Unfortunately, as Hemmings points out, Pontiac hit some home runs, but was still selling fewer than half of the cars Chevrolet was, and DeLorean felt the brand still had room to grow. In Hot Rod‘s recounting of the Banshee XP-833, Collins expressed an interest in designing a two-seat sports car. DeLorean reportedly told him that one day they’d get that chance.
As Hagerty writes, the XP was born from GM’s design department. DeLorean wanted the XP, but so did Oldsmobile chief engineer John Beltz. Both chief engineers hashed out the possible design of the XP, but Beltz ultimately gave up the chase, reportedly knowing that getting a non-Corvette sports car into production wasn’t going to be easy.
DeLorean went back to his engineers and they got to work coming up with a design brief. The Pontiac wouldn’t just be a sports car, but one that was cheaper than a Corvette, and therefore attainable by more people, including young people. And they would do it by raiding the GM parts bin, collecting about 70 percent of their sports car’s chassis from other GM vehicles.
In 1964, DeLorean and Collins presented the idea to GM president Ed Cole and chairman James Roche. Reportedly, DeLorean had a way to avoid getting told “no” by promising that he’d show off functional prototypes, cars that were supposedly already built, but actually weren’t. The XP reportedly impressed GM brass, but now DeLorean had to deliver on his word.
The Sports Car For All
Back with his team, DeLorean ordered two prototypes, the SP-5 and the SP-6. The former had a removable hardtop while the latter was a convertible. The SP-5 represented what would be the base model while the SP-6 was a hotter, more expensive example.
As DeLorean promised GM brass, these would not be non-functional models, but fully operational prototype cars. Two functional cars would be built, plus four non-functional mock-ups.
Collins explained to Hot Rod that the engineering team raided GM’s parts bin. These cars were supposed to be cheaper than a Corvette, after all. The engineers built a chassis containing a lot of A-body parts, including frame sections and the Salisbury-style 10-bolt live rear axle from the 1964 Pontiac Tempest. It’s noted that the chassis wasn’t mated to the vehicle’s body through the traditional body mounts. Instead, the engineers welded the chassis to the floors of the body. Apparently, had these vehicles reached production, they would have featured unitized construction.
Keeping the car shiny side up is a coil-spring double A-arm front suspension up front and a four-link suspension with a Watts linkage in the rear. It’s reported that while the engineering team took as many Tempest parts as they could, the suspension appeared to have been custom-made for the XP-833. As you’re probably guessing by now, the XP-833 wasn’t a sophisticated car. It even had pitman-arm steering without power assist and manual drum brakes at each corner. It’s estimated that 80 percent of the XP-833 comes from the GM parts bin.
The biggest bits of tech the XP-833 brought to the table were adjustable pedals, a double-hinged trunk lid, and a fiberglass body courtesy of Dow Cornin. Collins notes that the design was inspired by the Corvair Monza GT show car. The base model SP-5 was equipped with a 230 cubic inch straight-six good for 165 HP while the SP-6 convertible got a 326 cubic inch V8 good for 250 HP. Reportedly, the engineers envisioned the XP-833 having larger engines, including possibly a 389 V8 and a 421 V8.
It was wise for the engineering team to use a smaller V8 for the prototype car. This was a car that weighed 2,615 pounds and could have made 360 HP from a 389 Tri-Power V8. That’s almost 400 pounds lighter than an equivalent Corvette, which made 425 HP from a big block V8. Add in a dramatically lower base model price, $2,500 compared to $4,141 for a Corvette back then, and Pontiac would have been firing a shot across the Corvette’s bow.
In 1966 (some sources say 1965), Pontiac presented its case to GM brass once again. By now, DeLorean was the head of Pontiac, which gave him some extra pull. DeLorean pitched the XP-833 cars as Ford Mustang killers, not a rival to Chevy’s Corvette. Sadly, DeLorean’s clever marketing didn’t do much because even though the XP-833 was close to being production-ready, General Motors wanted nothing with it. The program was canned and the two functional XP-833 examples were destined for the crusher.
The Grail
Collins and Pontiac master mechanic Bill Killen saved the XP-833 duo from the scrapper by hiding them away in shipping containers. Years later, Killen would purchase SP-5 and Collins would take home SP-6. Before the cars went to their new home, Collins found some Banshee nameplates and slapped them onto the prototype cars, giving them a posthumous name other than XP-833. Both Banshees are essentially one-offs and cars you will never see anywhere else. These are cars that, if crashed, you wouldn’t find replacement parts for.
In 1988, the SP-6 changed hands from Collins to Chicago-based collector Joe Bortz. SP-5 has been passed around, leaving Killen’s possession and eventually ending up with Connecticut car dealer Lenny Napoli in 2006. Napoli, known for running Napoli Kia, paid $214,500 for the vehicle. Since then, Napoli has attempted to sell the car several times without getting any bites. The vehicle failed to sell for $750,000 in 2013 and again for the same price in 2020. It then failed to sell again in 2023 for an inflated price of $1,200,000.
This year, Napoli is back trying to sell the vehicle again. It was listed on Hemmings’ Make Offer platform where it has currently failed to gather an offer higher than $50,000. As of writing, Napoli still wants $1,200,000.
[Correction: An earlier version of this story said the Banshee was auctioned at Hemmings. It is instead listed on the site’s Make Offer platform, which may look like an auction, but is a type of classified listing that allows prospective buyers to cast offers and the seller to choose a buyer based on the offer price.]
As noted earlier, this XP-833 is the SP-5 base model car. It has a removable hardtop and comes powered by a 230 cubic inch straight-six good for 165 HP. That punches power to the rear end through a four-speed manual transmission. Napoli says the car has all of 1,498 miles on its odometer, and that is just from driving the car to shows.
This car is one of the few we’ve written about that meets even the traditional meaning of Holy Grail. It is the only Banshee hardtop in the world. So, if you want it, $1,200,000 or trade for another interesting vehicle is your price.
It’s noted that while the XP-833 didn’t go into production, parts of it did live on. The Opel GT borrowed some of the XP-833’s front-end work and two different model years of the Pontiac Firebird Trans Am also clinched some rear design elements. If you squint hard at a C3 Corvette, you might see some XP-833 in there, too. In Hot Rod‘s interview with Collins, it’s also noted that the Pontiac Solstice of the 2000s was built to more or less the same design brief as the Banshees were, making the Solstice a spiritual successor to the XP-833 project.
Of course, with a vehicle this expensive and this rare, it’s not going to be your daily driver. But it is a time capsule to what could have been. Had DeLorean succeeded in his mission, Pontiac could have launched a world-class sports car that, sure, may have challenged GM’s Corvette darling, but could have also allowed so many people enjoy a sports car without paying tons of money.
Do you know of or own a car, bus, motorcycle, or something else worthy of being called a ‘holy grail’? Send me an email at mercedes@theautopian.com or drop it down in the comments!
(Images: Lenny Napoli/Dragone Auctions)
GM passed on a lot of interesting cars because they were terrified of the Corvette losing a single sale. We’re lucky that the Camaro even exists.
I mean to be fair to GM, it’s a lot more than just a “squint” resemblance to the C3 that already would have been in the pipeline; and there’s no doubt that Pontiac would have gone Corvette hunting with it as soon as GM’s back was turned.
Corvette was the worst thing to happen to GM in killing advancement
This is awesome and wish it was made…it looks similar like the Corvette but still has unique features
Kramer: “All right! OK! Right, here we go. Yeah. OK, so… ‘For sale. A big,
juicy van.’ And, ooh, you gotta put down, ‘interesting trades considered.'”
Opel GT Same car nothing lost.
I would say this is what the Opel GT should have been.