The futuristic roof of the 2024 Cadillac Celestiq is so much more than a huge piece of glass

The Cadillac Celestiq is impressive for many reasons, even before the $300,000 starting price is mentioned. It has a massive 130-inch wheelbase, does 0-60 in less than four seconds, and lo and behold, it’s a land yacht with unparalleled luxury for a Cadillac. Part of that luxury is the huge glass roof.

The huge transparent structure is the largest piece of automotive glass in the world and it’s not just an expensive new way to get sunburn. It gives passengers almost an inch more headroom and it can be tinted individually above each passenger. If someone in the back doesn’t like the sun as much as the others, they can give themselves some shade.


This technology has been used on other vehicles before. It first debuted as an option on the Mercedes SLK (later SLC) roadster in 2011, and has since appeared in other Mercedes-Benz coupes. However, it has never been used that way. One of the visionaries behind the technology is Joe Harary, CEO of Research Frontiers. Harary’s company invented Smart Glass decades ago, and now it licenses the deceptively simple technology to several car suppliers.

Smart Glass is a film in which millions of nanoparticles are suspended. It is sandwiched between layers of glass in a laminated sunroof. When a very small amount of voltage is applied, light can pass through it. When the voltage is turned off, the particles return to a random position and no light can pass through. It can go completely bright, blocking 99.5% of all light and everything in between. It can also be layered if complete darkness is desired.

As Mercedes discovered at the SLC, the technology blocks not only light, but also heat from the sun. “They found that it actually lowered the temperature inside the vehicle by 18 degrees Fahrenheit,” Harary told me. That was a big plus for the German automaker. It continued to use it on several other gas-powered models, including the S-Class coupe, but the potential for EVs was more apparent. Harary recalls that Mercedes and car supplier Continental discovered: “Not only could you lower the temperature in the vehicle by 18 degrees, but you could also increase the range of an electric vehicle by about 5.5%” because the air conditioning couldn’t. would have to do. are used so much.

It was only relatively recently that GM became interested in the technology. It first made contact with Harary at an automotive glass conference, but it wasn’t until the middle of the 2020 pandemic that the Celestiq took formal shape. In fact, Harary’s last face-to-face meeting with GM took place after all of the automaker’s facilities were closed to outside visitors. “We met in the parking lot of a Pancake House, started our discussion there and had a nice pancake breakfast and continued,” recalls Harary. Sometimes we forget how strange the early days of the pandemic were. At the time, he says many details of Celestiq’s production still hadn’t been worked out. Even its price point. Keep in mind that this was just six months before the car was first teased at CES.

The Celestiq’s use of the film is interesting, but nothing revolutionary in terms of Smart Glass’s capabilities. As the car shows, different parts of a single piece of film can be dimmed independently of each other. While Cadillac uses this to create four zones for each passenger, it can also be used to display just about anything. Animations, images, it’s all possible. “You can do it in as high resolution as you want,” he explains. “If I wanted the Cadillac logo to flash in the roof, I could.”


The film is also not only capable of blocking light. It is a somewhat spongy material, which also makes it a good muffler in the glass. Combine this with the Celestiq’s quarter-inch-thick roof, and it’s sure to be a quiet place to be. “With electric vehicles, you hear road noise, especially at higher frequencies,” Harary said. His film can significantly reduce that, and also offers the above-mentioned range benefits.

He seems interested in buying a Celestiq with the technology. The CEO already has a Mercedes equipped with Smart Glass. “If our stock price continues like this, I can afford one,” he said with a laugh. “If I want to ride in ultimate comfort, I take the Celestiq out.”

Regardless of any car splurges, he clearly loves the technology. “I remember when I first pushed the button and served the first crude [smart window.] I thought it was magic. That was in 1987.”, he recalled. “Today, when I’m in my car and I just press the sunroof and it goes from dark to bright, I still feel the magic.”

Hopefully, for Cadillac’s sake, Celestiq buyers will too.

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