Your next car will throw shade on demand

Just like a Boeing 787 Dreamliner, future vehicles will offer dimmable windows.

Craig Cole Former reviews editor
Craig brought 15 years of automotive journalism experience to the Cars team. A lifelong resident of Michigan, he's as happy with a wrench or welding gun in hand as he is in front of the camera or behind a keyboard. When not hosting videos or cranking out features and reviews, he's probably out in the garage working on one of his project cars. He's fully restored a 1936 Ford V8 sedan and then turned to resurrecting another flathead-powered relic, a '51 Ford Crestliner. Craig has been a proud member of the Automotive Press Association (APA) and the Midwest Automotive Media Association (MAMA).
Craig Cole
4 min read
Gentex Dimmable Glass

Like magic, this fancy glass can be dimmed at the touch of a button.


Boeing's 787 Dreamliner has been flying commercially for about a decade now. The long-haul, wide-body passenger jet's carbon-fiber construction and efficient engines have made it a popular choice with airlines looking to cut their fuel costs. Helping reduce weight and further improve efficiency, the machine is also fitted with electrically dimming windows instead of traditional sunshades. In the next couple years, this clever feature could be coming back down to earth, making its way to road-going vehicles instead of just high-flying aircraft.

Yes, dimmable glass panels have been offered on select vehicles for a few years now. Mercedes-Benz's Magic Sky Control system comes to mind. It's been available on a number of models, and it's currently an option on the sporty SL Roadster.

But pushing this technology forward, at CES in Las Vegas this week, supplier company Gentex showed off several more ways to put dimmable glass to good use. This company serves the automotive, aerospace and other industries, plus it's the world's leading source of dimmable devices, which includes things like rear- and side-view mirrors. Its latest generation of this technology can block more than 99 percent of visible light and responds twice as fast as its predecessor. It's so effective, Boeing rival Airbus has signed up to start using the technology on its aircraft.

"Electrochromics is the science of darkening materials using electricity," explained Craig Piersma, director of marketing and corporate communication at Gentex Corporation. "So, it's basically a … proprietary gel that we sandwich in between two pieces of glass, and when a current flows through that gel it darkens." Take the electricity away and it's fully transparent. His explanation makes the technology sound deceptively simple; in reality, it's a bit more complicated than that. "There's a lot of unique coatings and things that go into it," he added.

Gentex Dimmable Glass

This technology has been used on aircraft for a number of years.


Making waves at CES 2020, the big news from Gentex is that it revealed electrically dimmable side glass. "So, this is the first time we're showing [it]," said Piersma.

Applying this technology to a vehicle's windows is more challenging than using it on a sunroof. Piersma explained that the glass in this application is curved, it moves up and down and it's got to be pretty thin. Beyond those pitfalls, with a sunroof there are no optics to worry about; if your view of the clouds above is slightly distorted it's not a safety issue. "When you have two pieces of glass here you don't' want to create a funhouse effect," he said. "Those two pieces of glass have to be bent perfectly the same."

Dimmable side glass could drastically cut down on unwanted glare, but this simulated window tint is not always legal. "Because every state has different requirements for how dark these windows can go, you could actually go so far as to geofence, to understand where the vehicle is, and have it automatically adjust," said Piersma. If, for instance, New York allows tint, but nearby New Jersey does not, your car could automatically make its windows transparent when crossing the border.

Jumping from aircraft to automobiles , there's nothing really new here. Piersma said some subtle changes have been made to their chemical formulations, but the bigger advancements are really on the glass side of the equation. Handling large sheets of this fragile material and manufacturing pieces to exacting tolerances has been a problem in the past, but it's one that should be sorted out.

Gentex Dimmable Glass

Automatically dimming head-up displays could be a game-changer.

Craig Cole/Roadshow

Aside from dimmable windows, this electrochromic technology could also be put to good use on combiner-style head-up displays; those are the ones with separate, pop-up reflector panels. Gentex also showed off a concept version of this at CES. With a few sensors, the glass could be made to automatically dim if there's glare, so the graphics are always visible.

On the subject of bright light, German supplier company Bosch also revealed some glare-reducing tech in Las Vegas this week. The firm's new Virtual Visor consists of a transparent, flip-down LCD screen, a face-tracking camera and plenty of software. Put it all together and this system can selectively prevent light from blinding a driver. It's pretty neat.

Another clever use of electrochromic glass is hiding small displays or even cameras on a car's or truck's B-pillar. This could be particularly useful on ridesharing vehicles or even EVs, where a state-of-charge indicator would be handy.

Gentex is currently in talks with a number of automakers about getting more electrochromic glass out on the market. Piersma said dimmable sunroofs should show up relatively soon, but "side windows will probably be two to three years."

Dimmable windows could be coming to a car near you

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Watch this: Take a look at what your next car's rearview mirror will do