The history of the automobile is littered with tragedies: innovative vehicles far ahead of their time, crushed by outside forces or a lack of interest, butted right up against engineering hack jobs pushed into production by cynical marketers that somehow manage to sell like hotcakes. It’s the nature of the industry, a place equally driven by irrational wants from the consumer and deeply rational economic needs on the part of the producer. That’s not to say that it’s impossible for cool cars to actually make it onto dealership lots, just difficult. Take the upcoming fifth-generation Toyota Supra for instance: it offset the costs of building a brand-new niche product (because let’s face it: this isn’t going to be a volume seller), Toyota had to partner up with BMW in order to split development costs. That’s often what stops most slinky sports car projects. No matter how high consumer interest, cost-ratio analyses are going to decide whether or not something gets built.

Then there’s the cars that did somehow make it through the fiery crucible that passes as the development process. Building and designing cars is a ruinously expensive, complicated affair, so making sure that the end product makes enough money to offset those costs is vital. Sounds like common sense, I know, but you’d be surprised how often companies get it wrong. That’s certainly the case for some of the entries on the second half our list. The others however, were unbridled successes in spite of some massive flaw, whether that be shoddy engineering or something less tangible.

20 Audi quattro

via performancedrive.com.au

In the holy pantheon of rally-bred sports cars, few are saintlier than the OG Audi Sports quattro, a stripped-out turbocharged pitbull with the aerodynamic finesse of a brick. It’s probably the company’s most iconic car, so 21st century reincarnation couldn’t be anything less than magnificent.

Thankfully, 2010’s Audi quattro (yes, the ‘q’ is supposed to be lowercase) concept was absolutely breathtaking.

In stark contrast to the “more is more” philosophy that dictates modern sports car design, the quattro was a masterwork in minimalism: built on a massively shortened RS5 chassis, the concept was employed an exotic mix of aluminum and carbon fibre to keep weight down to a mere 2,866 lbs. In keeping with tradition, the quattro was powered by a turbocharged 2.5 liter inline-five, plucked from the nose of the TT RS, which sent its 403 hp to all four wheels through a six-speed manual transmission.

19 Cadillac Sixteen

via motor1.com

In the early 2000s, before Cadillac had designs on chasing the German Big Three with a lineup of hard-riding, Corvette-powered sport sedans, they were perceived as little more than a motorized Barcaloungers, ideally suited to retirees with oversized flowered shirts and tweed trilbys. The Sixteen could have changed all that: revealed in 2003, this ultra-lux sedan would have been worthy of Cadillac’s old “Standard Of The World” tagline, and steered the company toward being trend-setting purveyors of art-deco marvelousness. The beating heart of the car was a sixteen-cylinder mill displacing a staggering 13.6 liters (in a presumably futile bid to cut fuel consumption, Cadillac fitted it with cylinder deactivation tech that could shut down between eight and twelve cylinders). Power rang in at 1,000 hp and over 1,000 lb ft of torque, which should have been enough to bring this 5,005 lb land yacht to speed toute suite.

18 Honda Dualnote

via oldconceptcars.com

Also known as the Acura DN-X, the Honda Dualnote was a scarily prescient picture of the current performance car landscape. Get this: despite being revealed in 2001, the Dualnote featured a seriously innovative hybrid powertrain, comprising a mid-mounted 3.5 liter naturally-aspirated V6 (good for 300 hp) mated to a trio of electric motors. Honda promised all-wheel-drive, 42 mpg fuel economy, and a total system output of 400 hp.

Sound familiar? That’s right, despite being revealed 15 years apart, the Dualnote’s specs are eerily similar to those of the second-generation Honda NSX, which, in fairness, does make an extra 100 or so horsepower.

Mind you, that’s immediately offset by the concepts added practicality: somehow, Honda managed to squeeze in an extra pair of seats and doors, making this a high-performance hybrid sedan, a niche that’s woefully underexplored even today.

17 Infiniti Q50 Eau Rouge

via motorauthority.com

The Nissan GT-R is probably one of the most important cars of the new millennium, a technological tour-de-force that’s still more than capable of matching the performance machine twice or even thrice its price even after more than a decade on the market. Imagine taking that capability and transplanting it into the body of a four-door sedan. Such was the thinking behind the Eau Rouge concept, which, upon its reveal in 2014, seemed poised to drop a shock and awe campaign on the likes of the BMW M3 and Mercedes C63, courtesy of a 3.8 liter twin-turbo V6 producing 560 hp. Named after an iconic, super-fast corner at Belgium’s Circuit de Spa-Francorchamps, the Eau Rouge backed up its motorsports-inspired moniker with plenty of carbon fiber jewelry and a rear bumper-mounted brake light from Red Bull’s RB9 F1 car.

16 Kia Track’ster

via gtplanet.com

The annoyingly named Track’ster made its debut at the 2012 Chicago Auto Show, serving as a much-needed shot of adrenaline to Kia’s overly cutesy Soul lineup. With looks supposedly inspired by a bulldog, the concept backed up the promise of its super-wide haunches with a 250 hp turbocharged inline-four.

That power was delivered to all four wheels (19-inch HRE-K1s wrapped in grippy Michelin Pilot Sport PS2 rubber, 245s up front and 285 width at the rear) through a six-speed manual gearbox.

Meanwhile, the driver and sole passenger would be safely ensconced within a motorsport-inspired bubble, featuring a trio of containers for tools, racing gear, and your helmet instead of back seats.

15 Lincoln MK9

via motor1.com

It’s been a long while since Lincoln had a two-door luxury coupe in their lineup: blame changing consumer tastes and a lack of financial viability. Still, there’s something to be said about the impact that a proper halo car could have on people’s perception of the brand. Revealed at the 2001 New York Auto Show, the V8-powered MK9 was intended to be a standard-bearer for domestic luxury. Designer Gerry McGovern (currently the Design Director at Land Rover) deliberately channeled the long and low proportions of Continental Mark II from the late fifties. The interior was similarly old school: finished in the style of a cigar smoke-stained study, the interior featured perches inspired by the Eames Lounge Chair along with an acre's worth of Marlboro Red leather and Dark Cherry wood veneer.

14 Lotus Esprit

via carpixel.net

A couple of years back, low-volume sports car maker Lotus got ambitious. Fueled by the dreams of former CEO Dany Bahar, the company sought to become Hethel’s equivalent to Ferrari: at the 2010 Paris Motor Show, they announced five new models to arrive over the following five years.

The Esprit was to be the range-topper, built to do battle with the Ferrari 458 and give up nothing in terms of performance or prestige.

To that end, Lotus opted to develop the Esprit’s engine in house, an incredible feat for such a small company. A working, naturally-aspirated 5.0 liter V8 prototype was built, supposedly dyno-rated at 600 hp. Unfortunately, money for the project ran out in September 2014, two years after Bahar was ousted as CEO for allegedly misusing company funds.

13 Nissan iDx

via nissan.co.uk

At heart, I’m a JDM fanboy, so few cancellations have stung me as much as Nissan deciding not to put the iDx into production. In case you haven’t noticed, the market isn’t exactly flush with back-to-basics, RWD sports compacts, which makes the car’s absence all the more apparent. Revealed in 2013, Nissan showed off the concept in two flavors: the Nismo, pictured above, was equipped with a limited-slip differential, stripped-out interior, turbocharged 1.6 liter engine, and a six-speed manual, while the chilled-out Freeflow came bundled with a more eco-friendly naturally-aspirated/continuously variable transmission powertrain combo. Unfortunately for fans of Datsun 510-inspired bundles of joy, the project was shelved after Nissan announced that it couldn’t justify the cost of developing a single-use platform.

12 Toyota Alessandro Volta

via knobiobiwan.blogspot.com

The Alessandro Volta was named after the Italian chemist who invented the battery. However, despite the expectations set by that moniker, this isn’t a fully electric vehicle: the concept was unveiled in 2004, back when the Model 3 was a twinkle in Elon Musk’s eye.

Instead, the Volta, styled by famed design house Italdesign-Giugiaro, employed a modified version of the hybrid powertrain for the Lexus RX400h.

Combined output from the 3.3 liter naturally-aspirated V6 and pair of axle-mounted electric motors was a stout 408 hp. With an electrically-assisted AWD system and carbon fibre chassis, this Toyota was intended to be an eco-friendly way to enjoy scorching performance: 60 MPH came and went in just over four seconds, while top speed was limited to 155 MPH.

11 Volkswagen Bluesport

via roadandtrack.com

The Bluesport could have been Germany’s answer to the MR2 question, spreading the gospel of affordable, mid-engine fun to the motoring masses. Instead, its now merely regarded as a fascinating "what-if" scenario.  It made its debut at the 2009 North American Auto Show in Detroit in almost production ready-form: the car’s specifications were almost fully fleshed out. Power came courtesy of a 2.0 liter TDI engine making a stout 180 hp and 260 lb ft of torque, delivered to the rear axle through a six-speed dual-clutch gearbox. With a curb weight well under 2,700 lbs, performance was pretty darn brisk: VW quoted a 0-60 time of 6.2 seconds and a top speed of 140 MPH.

10 Aston Martin Cygnet

via autoya.info

In a desperate gambit to lower their lineup’s average CO2 emissions, Aston Martin decided to slap their corporate face on Toyota’s iQ city car (sold here under the Scion name) and give it a pretentious name, pulling the wraps off the concept in 2009.

Now, don’t get me wrong. The iQ is a wonderful car that accomplishes what it was designed to do with considerable aplomb: squeezing four seats inside a space only fractionally larger than a Smart Fortwo is basically witchcraft.

However, putting quilted leather seats within that environment does not a luxury car make. When you’re asking the equivalent of nearly $40,000 for the "privilege," it's no small wonder that the Cygnet is widely regarded as one of the most embarrassing cars of the 21st century.

9 BMW 5-Series GT

via automobilesreview.com

A lot of people in the enthusiast community have accused BMW of having misplaced its mojo in recent years. When you look at cars like the 5-Series GT, it's hard to disagree with them. Revealed in concept form at the 2009 Geneva Auto Show, the car somehow managed to distill the footprint of an SUV, the off-road capability of a luxury sedan, and the headroom of a low-slung coupe into one staggeringly inefficient package. Billed as a  new concept not just for BMW, but for the entire automotive world," the GT did in fact defy classification. Whether or not that’s an asset, well, that’s up to you.

8 Chevrolet SSR

via oldconceptcars.com

Through much of the early 2000s, GM went retro-crazy with concepts: there were kitschy reinterpretations of the Nomad station wagon and Bel Air convertible (the latter of which was somehow based on the same ladder frame chassis as the Suburban SUV) as well as this, the SSR, which paid homage to the gorgeous Advance Design trucks of the late 1940s.

It was the only survivor, and also somehow the lesser of three evils.

That’s not to say that people were thrilled: by the time sales began in late 2003, three years after the concept’s unveiling, retro-fatigue was beginning to creep in, and the distinctively-styled SSR was hit harder than most. Only 9,000 were sold in its first year, with a total production run of under 25,000 units.

7 Chrysler Pronto Cruizer

via youtube.com/officialrallyHD

I don’t hate the Pronto Cruizer for what it is, but what it represents. The blobby, soft-edged styling seems so inauthentic to me, a lazy way to recall a bygone era of hot-rodding: it’s a wheeled embodiment of a flame-embroidered silk shirt, wraparound sunglasses and frosted tips, seemingly hand-crafted to aggravate me. But the Pronto Cruizer’s greatest sin? Bringing the PT Cruiser into the world. Now, I shouldn’t really blame Chrysler for being swept up in the retro wave: it was a short-lived, hugely profitable wave, instigated by the success of cars like the New Beetle and Mini Cooper Hatch. What I can blame them for is building a poorly-engineered scrapheap, seemingly built entirely from Soviet-era plastics and a pair of popsicle sticks.

6 Dodge Avenger

via supercars.net

The Avenger is a popular punching bag in the automotive world, having drawn ire for its unmistakable mix of grey plastic, more grey plastic, and giggle-worthy name.

It's hard to believe that it could have been worse, until you take a look at the concept, unveiled at the North American International Auto Show in Detroit in 2003.

Mating the blocky detailing of the later Sebring-based sedan to the form factor of an SUV is never going to yield a sleek silhouette, so bless Dodge’s heart for trying to smooth out the concept’s profile with a coupe-like roofline. I mean, my goodness, crisis averted. A proto-BMW X6 developed by early 2000s Chrysler? Yeesh.

5 Land Rover Evoque Convertible

via carpixel net

I have a lot of respect for Land Rover: the company forged its reputation building cars that could get you basically anywhere in air-conditioned comfort. Heck, I even like their more fashion-forward offerings like the new Velar, and yes, the Evoque. However, building a convertible version of the latter is simply a step too far. Revealed as a concept in 2015 and pushed onto production lines two years later, the Evoque convertible is seemingly built and engineered to appeal to no one. Obviously, the camo-clad expedition-ready purists aren’t going to like it, but I think that fans of the regular Evoque will prefer the closed-roof car’s sleeker profile and greater practicality, and probably won’t attempt to explore the car’s all-terrain capability at the risk of covering the chic leather-lined cockpit in mud.

4 Mini Coupe

via conceptcarz.com

Even the usually fiercely patriotic British motoring press had little to recommend the Mini Coupe, revealed in concept form at the 2009 Frankfurt Motor Show, over any number of comparable rivals or, indeed, the regular Mini hatch on which it was based. It’s hard not to see why: not only was the Coupe less practical than the three-door, being a dedicated two-seater, it was also deeply ugly, with a bubble greenhouse supposedly inspired by backwards baseball caps. Why anyone at the company thought that that was a good source of aesthetic inspiration is an absolute mystery.

3 Nissan Qazana

via cardesignnews.com

It’s a source of great personal shame that I don’t hate the Nissan Juke. Rightly reviled in the mainstream media for its mix of bizarre styling and limited practicality, I suppose I’m just indulging my inner hipster when I say that I wouldn’t immediately dismiss the idea of owning one. Mind you, I find the Qazana concept, which made its debut in 2009, to be a slightly more attractive proposition, not the least for its less ridiculous name. However, much affection I have for the bug-like Nissan, I’d be an idiot to ignore the legions of ugly crossovers that its success inspired, which is a large part of the reason for its inclusion on this list.

2 Pontiac Aztek

via carstyling.ru

The Aztek concept, unveiled in 1999, wasn’t exactly pretty. In comparison to the production-ready vehicle that followed it, its practically a Ferrari 250 GTO. Discussing aesthetics is a tricky thing over the written medium, so bear with me: it’s the culmination of several small changes that turned the rugged, edgy concept into a wheeled leper, chief among them being fatter proportions and a much greater reliance on grey plastic cladding. So, like many other entries on this list, the Aztek concept isn’t here for what it is, but what it brought into this world.

1 Volkswagen Concept 1

via cardesign-news.com

With the wave of retro-inspired economy cars that it inspired, its easy to forget just how flawed the Volkswagen New Beetle really was. Based on the much-maligned fourth-generation Golf, the car was plagued with electrical gremlins.

Then there was the interior, which sported one of the most embarrassing accessories to ever survive the journey from drawing board to assembly line: a miniature flower vase plopped directly behind the steering wheel in a desperate bid to pander to female audiences.

The Concept 1, designed by J Mays (former Group Vice President of Global Design at Ford)  and revealed at the 1994 North American International Auto Show, was a far more restrained proposition.  With its economy car roots (being based on the smaller Polo hatchback), it was also more in line with what the original Beetle represented.

Sources: cartype.com, oldconceptcars.com, motor1.com, topgear.com, supercars.net