When General Motors was formed way back in 1908, they very rapidly built a massive corporate empire. During the following decades, this largest auto behemoth out of Detroit commanded the production lines of dozens of marques across the globe, and were responsible for everything from the quintessential Muscle Car through to the family saloons and fast, large, well-appointed cruisers that had come to characterize the Great American Auto Boom. Their size provided them with capital for unending experimentation across the breadth of the motor industry’s every conceivable branch.

Despite that, not even the largest manufacturing corporations are entirely exempt from engineering head-scratchers, and designs that miss the mark; with hundreds of various models built over a hundred plus years by many automotive brands, some oddballs were inevitably going to make customers wonder “What the heck was that for?” So with no further ado, here are twelve of GM’s weirdest, most daring, and most memorable auto experiments.

1. GMC Motorhome

Motorhomes typically do not fall within the definition of ordinary passenger auto mobiles, yet GMC’s interpretation from the 1970’s was much more closely related in terms of running gear than would otherwise be expected, for the engineers at GM started their development in the latter half of the sixties of this motor-loving motorhome; instead of having engineers resort to a heavy, truck like chassis for the auto mobile upon which to base their car. Rather, they derived mechanical aspects primarily from an Oldsmobile Toronado.

What Made It Unusual:

• Based on Oldsmobile Toronado platform
• No central driveshaft used
• Lower floor, spacious interior
• Big-block V8 transaxle power
• Rear wheels on air springs

This is also where the removal of a central driveshaft entirely re-wrote the underlying way the vehicle could be built from scratch and create that “huge interior” that looked more like a motorhome lounge than anything else on the road at the time. A monster-big-block V8 transaxle propelled that vehicle and was engineered to allow for such a low-floored design, also benefiting from it and only having to run a pair of single (not doubled) rear airbags to achieve the non conventional arrangement which provides one of the most sublime highway rides you will find. You can see from the number of them being kept on the road today why so many people would buy these vehicles.

2. Pontiac Aztek

It made a striking appearance at the 2000 Detroit auto show, where it would have been a hit if the wrong reasons were what GM was going for. Auto journalists, along with a bewildered public, was bombarded by bold, lurid body panels, a bulbous body, peculiar dual headlights. Young, adventure seekers, the primary market it was aimed at, was coaxed into buying one of GM’s very first unique items; either by opting for an auxiliary self-consistent cooler that unzippered or for a tent that fitted to the outside of its rear hatch.

The Aztek’s Infamous Reputation:

• Debuted at 2000 Detroit Auto Show
• Gaudy panelling, awkward proportions
• Removable Center console cooler
• Custom rear hatch tent
• Standard GM mechanicals underneath

Beneath the polarising bodywork, the Aztek was actually built with boring, everyday GM running gear and was completely standard in its interior design. Alas, the dramatic aesthetic was too scary for would-be buyers and immediately made the Aztek into a running joke amongst the automotive enthusiasts. The vehicle is one of the biggest infamous design mistakes GM has ever made.

3. Chevrolet SSR

After the El Camino (a car-basedute), Chevrolet brought back its modern equivalent at the turn of the 2000s as the retro SSR. It looked to brand history for inspiration, referencing Chevrolet’s 1940s Advance Design pick-ups with bulging, chrome-trimmed fenders and broad slatted grille, which gave it a low-slung, hot-rod type appearance. Its performance failed to please hot-rods in early models as it shared a regular 5.3-liter Trailblazer V8.

SSR’s Identity Crisis:

• Retro styling from 1940s trucks
• Used 5.3-liter Trailblazer V8
• Later got 6.0-liter Corvette engine
• Confused sports car vs pickup
• Only 24,000 units sold

Even the eventual switch to the new 6.0L Corvette LS V8 as a performance upgrade-intended to afford the line some legitimacy-could not help its prognosis because the buyer didn’t quite know if it was a sports car or a pickup; the simple fact is it was hard to categories so owners struggled to properly position it to a potentially massive audience with a strong taste for nostalgia. The vehicle could have even been rescued with a power folding cargo lid or power folding roof panel and, still wouldn’t have helped the auto mobile.

4. Chevrolet Corvair

Volkswagen’s success with their Beetle spurred Chevrolet on to produce a rival of their own, they released a rear-engined Corvair in 1960. Innovative at the division of American cars. It had a rear-mounted, air-cooled flat-six, directly coupled to a transaxle driving the rear wheels. The division, as such, was also diverse; from coupe to saloon, saloon to estate car, and through to a van and pick-up vehicle.

Corvair’s Radical Design:

• Rear-engine, air-cooled flat-six
• Countered the VW Beetle
• Diverse line-up wagons, vans, trucks
• Side-loading bed on truck
• Doomed by Nader’s safety book

The truck had a side loading bed. The rear mounted flat-6 replaced the usual tailgate area and eventually the Monza model received a 150hp turbo engine. Strict emission rules and escalating production expenses proved to be the fatal blow for the platform. Also, consumer advocateship Nader pointed the car out in his popular book “Unsafe at Any Speed,” speeding up the end of this unconventional experiment with a rear engine.

5. Oldsmobile 442 (1978-1979)

A definitive muscle car touchstone, this actual Oldsmobile 442 was once regarded as among America’s quintessential muscle car stalwarts with its 400hp or equivalent Big Block V8 putting out the brutal performance that a true street machine should. Its credibility rested largely upon an “in your face” method for producing raw street power where few others at the time came close; it’s that legacy which made what happened next all the more surprising for longtime devotees of the badge. Quite bizarrely in 1978 the brand name was now attached to a simple body kit whose lineage was completely unrecognisable with a cosmetic package found applied to the Aero back Cutlass Salon body style and had very little to do with muscle car power at all.

A Legend’s Strange Turn:

• Once a true muscle car
• Became a cosmetic package
• Used Cutlass Salon Aero back body
• Fixed rear glass, tiny trunk
• Base V6 made only 105hp

Although there was a fastback roofline, the rear glass wouldn’t lift, the only access for the trunk cargo being a minuscule boot lid. The range of engine options had also taken a hit due to the constraints of the Malaise era with the bottom spec models using an economical 3.8-liter V6 that produced just 105hp. This was such an abrupt change, it just seemed to have removed a performance legend and given a strangely-styled, underwhelming mid-size coupe instead.

6. GMC Envoy XUV

Between the great SUV boom of the nineties and the new millennium automobile engineers have been really pushing the envelope to differentiate their large utility vehicles, but GMC took it to the extreme for the Envoy XUV. They basically merged a full-size SUV with a truck bed (that didn’t extend). Eliminating the rear seating arrangement and installing an easy-clean moulded plastic load floor, they have done it all.

SUV Meets Pickup:

• Combined SUV with pickup utility
• Dropped third-row seating
• Washable plastic cargo floor
• Dual-function swinging/dropping tailgate
• Pulled after just two years

The double-duty tailgate could swing open like a door or lie flat, and the disappearing rear roof exposed an open cargo bed. This could be a neat idea, but gave up two seating positions while giving little functionality better than a normal truck bed. Unsurprisingly, it never gained many fans, and only saw two model years from GMC before being withdrawn.

7. Chevrolet Series M Copper Cooled

The early 1920s marked a crazy developmental stage in car engineering and it was in these years that the Delco leader, Charles Kettering, put forward an even wilder air-cooled engine plan. He was keen to eliminate money-stealing liquid-cooling and so he applied the high conductivity of copper to cylinder fins to produce this cooling solution for automotive purposes and combined with the use of a large cooling fan and cleverly designed metal ducting the power source was intended to propel the cheapest of the cars that Chevrolet was producing.

An Engineering Disaster:

• Proposed by Delco’s Charles Kettering
• Copper fins replaced liquid cooling
• Massive fan, special ducting used
• Broke down before leaving factory
• Roughly 2,000 units scrapped

Unfortunately nothing could go quite so planned and reality could simply not keep up and showed very quickly just how ambitious and out of reach the designers’ original concept actually was; poorly constructed to the point where it literally could not make it out of the factory without falling to bits and nullifying the concept altogether, it was impossible to even begin correcting such severe fundamental issues. After having constructed anywhere from between 1,000 and 2,000 of these awful looking and badly thought out vehicles they had nowhere to put them (customers were mercifully not to be inflicted with factory floor break downs themselves) and were unable to sell on any on to dealerships as such the venture clearly had reached an absolute end and was sensible cancelled before there were many more damaged reputations.

8. Chevrolet Vega

In the 1970’s Chevrolet started making the slick economy Vega. But it’s most fascinating element, and most peculiar mystery, is the way it was transported to the dealers. In order to fit as many cars as possible within the weight limits of the shipping cars engineers designed Vert-a-Pac train cars in which 30 Vegas were loaded with their noses pointed directly at the tracks, pushing the typical 18-car volume way up.

The Vert-a-Pac Solution:

• Shipped 30 cars nose-down
• Increased standard 18-car capacity
• Baffled oil pans installed
• Washer reservoir angled 45 degrees
• Fuel system modified for tilt

Astounding engineering was also put into vertical shipping that prevented the fluid from spilling. Engineers put baffles in the oil pan and tilted the windshield washer fluid reservoir at 45 degrees and implemented back edge battery covers. And the carburetor and fuel system was adjusted to make the fuel drain back into the fuel bowl when the car was laid flat. That was a problem many other manufacturers did not attempt to solve.

9. Cadillac Allante

At the close of the 1980s when trying to head off ballooning imports of German luxury auto mobiles, Cadillac enlisted the renowned Italian coach builder Pininfarina to pen a sleek roadster body. Instead of flying or sailing the bodies back over the Atlantic however, GM arranged the absolutely obscene 7,000-mile-long air bridge, perhaps the strangest factory logistics operation in the history of automotive development.

The 7,000-Mile Air Bridge:

• Body built by Pininfarina, Italy
• Flown 7,000 miles via 747s
• 56 bodies per flight, crated
• Assembled in Michigan finally
• Base price hit $54,000

The modified 747’s that took at least fifty-six car body-only, aluminium-crated bodies, to Michigan to have the running gear bolted on could have been built in a workshop: it just sounds more like aerospace then car production. The exorbitant cost of transporting completed bodies across the Atlantic rather than shipping them through conventional means resulted in adding astronomical cost per car off the line; this outrageously logistically inept program resulted in the $54,000 area as a starting price that most people, even long-term Cadillac buyers, would never consider for so costly a product.

10. Cadillac ELR

When major companies cross-share core technology among their brands, the payoffs can be significant. Cadillac’s ELR, however, ended up being a spectacularly expensive mistake. Built on the plug-in hybrid Volt from Chevrolet, the ELR fitted an undersized driveline with angular body work and opulent leather interior to carry hybrid tech into luxury, all with an expensive sticker on the back.

An Overpriced Misstep:

• Based on Chevrolet Volt platform
• 207 horsepower, 4,000 lbs heavy
• Only 39-mile electric range
• Priced $75,000, $35k over Volt
• Averaged just 93 sales monthly

Now its 207 HP wasn’t too shabby on paper for a coupe luxury compact, but after it did the duty you watched, that muscle begin struggle through the bulky 4,000 lb coupe, things got even better/worse when the laughable 39 mile all-electric mileage was used up a lot quicker than anticipated; by then, and since then, the tiny 83 HP gas engine puttered around barely offering enough power to keep things in gear at the stated pace. And after the outlandish $75,000 price, an additional $35,000 in difference above its Chevy sibling for what is, what amounted to, a new rebadged vehicle, buyers can hardly complain that it only achieved an average 93 per month before softly exiting the product family.

11. Chevrolet HHR SS Panel Van

The true win was in the retro style wagon versions. They gained a surprisingly dedicated following for its nostalgic feel alone. When these geniuses also decide to marry business practicality with brute force in a cargo-based window-is-gone, then something crazy happened; taking something already designed to ferry stuff around and turn it into unpredictable territory.

A Delivery Van Gone Rogue:

• Windowless commercial panel van
• 260-horsepower turbo engine fitted
• Turbo four ill-suited for hauling
• Compact platform, limited capacity
• Only 216 units built

The high-revving, turbocharged four-cylinder just wasn’t a benefit for serious hauling in that van, as it was set up more for going fast than anything else. Especially in a small chassis that doesn’t have capacity for much more than two people, the difference between expectation and reality was even more obvious when you started putting it to work. While many were expected to be reliable utility vans, they ended up more suited to racing around on weekend getaways.

12. GM EV1

Long before electric vehicles, of all sorts, inundated the automotive market, GM tested a visionary zero-emissions experiment with the EV1 back in the late-1990s. Offering an output of 137 electric horsepower’s by way of a lead-acid battery, the slim and modern, teardrop-styled two-seater can get 60 miles between charges with a very low drag coefficient of 0.19.

Ahead of Its Time:

• 137-horsepower electric motor used
• Lead-acid battery, 60-mile range
• Drag coefficient of just 0.19
• Offered only through leases
• Fleet later mostly crushed

Since battery technology was just about as crude then as it is now, it’s a wonder that the designers put as much engineering effort toward pure aerodynamics in the pursuit of performance as they did. And GM never tried selling it, but solely leasing on the GM EV1-and then destroyed almost the whole lot of the aerodynamic little teardrop coupe-solidifies it in automotive legend.