5 On Your Side

Without warning, sunroofs shatter into 'a million pieces'

Posted November 1, 2012

The fresh air, light and open feel – for many car buyers, sunroofs are a must have.

But plenty of owners are finding the must-haves might bust – big time.

Niki Wheeler said she was in her car when “all of a sudden, it was like I heard a gunshot. And it was so loud.”

The bang was the sunroof on her brand new Kia Optima. It exploded as she drove down busy U.S. Highway 1.

“It had literally shattered into a million pieces,” she said.

The saving grace was that the sun roof visor was closed.

“If the canvas hadn't been pulled, not only would I have gotten hurt, seriously, but I would have got in a wreck,” Wheeler said.

She called her husband, and he – like the dealership – said something must have hit the roof.

“I would have seen something or heard it,” Wheeler said. “But it wasn't like that."

And it wasn't like that for dozens of others.

Our 5 On Your Side investigation found complaint after complaint about exploding sunroofs. Drivers describe that loud gunshot noise, then shattering glass, with no signs of any bullet, rock or road debris having hit.

"From BMWs to Kias, to Fords,” said Neill Wheeler, Niki’s husband. “From Denver to California to North Carolina, there's no rhyme or reason for the who, what, when or where. Just sunroofs exploding while people are riding down the road."

Since 5 On Your Side started looking into this, the National Highway Traffic Safety Administration opened an investigation into shattering sunroofs on the 2012 Hyundai Veloster.

So far, the agency has complaints from 11 drivers.

“I've had five cars that we've replaced the sunroofs,” said Chris Latham, owner of Glass Solutions. Sunroof Sunroofs unexpectedly explode into 'a million pieces'

Latham, who’s been in the glass replacement business for 34 years, said the common denominator is tempered glass. It's designed to break into tiny pieces, instead of large shards, for safety. But it breaks easily.

“And that's what falling on their heads if they don't have the sunscreen,” Latham said, breaking a piece of tempered glass to demonstrate the shower of pieces.

Laminated glass, used primarily in windshields, doesn't break like that. It cracks and spider-webs because a thin layer of plastic in the middle holds it together.

Latham demonstrated by striking a piece of laminated glass, which doesn’t shatter.

“And I'm hitting that a lot harder, but you don't see it disintegrate," he said.

As for what's causing sunroofs to explode, there isn't a clear answer yet. But Latham shares the thoughts of other experts we talked with and tracked online.

First, cars are built more air tight than ever before. That could contribute to some of the failures. Also, more and more glass is being manufactured in places such as China and Mexico. While it meets standards, it's thinner and lighter.

But the biggest and perhaps most important factor is temperature change. Many of the reported sunroof explosions happened on hot days, especially after heat was trapped between the sunroof and a closed visor. Some sunroofs shattered on extremely cold days, just not as many.

One possible solution: On hot days, keep the visor open a little so heat doesn't build up.

"You know the heat is coming in, but with that being said, it's distributing the heat throughout the car instead of being trapped in an inch space," Latham said.

Then before you drive, vent the sunroof or other windows.

As for the Wheelers and the shattered sunroof on their Optima, Kia sent a statement saying the company "has not opened an investigation regarding sunroof glass failure" and that damage claims are "handled on a case-by-case basis."

The couple believes it’s time for the federal government to get involved.

“Oh, I think it's absolutely a defect,” Neill Wheeler said. “I can't tell you exactly what the defect is, but again researching online I’ve seen where the same vehicles have exploded more than once."

"I just really hope that someone looks into it,” Niki Wheeler said. “So that nobody gets hurt."

5 On Your Side also contacted the National Highway Traffic Safety Administration about the concerns. They gave us a one-line statement, saying they “don’t comment on open investigations.”

Anyone with a sunroof that has exploded can file a complaint with the administration online.



This story is closed for comments.

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  • piene2 Nov 6, 2012

    Who counted the million pieces?

  • Six String Nov 5, 2012

    CooperHayes: :-) Get gov't out of our lives. Until the sunroof shatters or a hurricane hits New Jersey.

  • thefensk Nov 2, 2012

    I think it might be the heat or the scratches or the nickel sulfide. It might be all of these things in one way or another but most likely it has something to do with installation tolerances ... however they are attached and installed they are likely not allowing for adequate expansion/contraction at the connection points. Faulty gaskets, or installation errors ... I bet it ties into something like that, which could easily provide a stresspoint that could be further complicated by any of the other potential "causes."

  • CooperHayes Nov 2, 2012

    "The couple believes it’s time for the federal government to get involved."

    Really? The government? Shouldn't the private sector and local churches take care of this?

  • AtALost Nov 2, 2012

    " Also, more and more glass is being manufactured in places such as China and Mexico. While it meets standards, it's thinner and lighter."

    It's not the heat, it's the poor quality glass. I've had sunroofs for 20 years. I always close the visor on hot days to cut down on the temp inside the car. I'm sure temperature plays a part, but that's only because the thin, cheap glass can't handle it. Sad that the price of everything rises while the quality diminishes and we encourage the behavior by continuing to send jobs to countries that care nothing about our safety.

  • pinball wizard Nov 2, 2012

    Nickel sulfide - look it up and tempered glass.

  • IBleedRedandWhite Nov 2, 2012


    Apparently you have never been in a car when tempered glass shatters. It does sound like a gunshot. I was driving in Charlotte on I-77 in my Jeep when all of a sudden out of nowhere the driver's side glass shattered. Sounded just like a gunshot. I literally pulled the car over and searched for a bullet or exit hole on the other side of my car. Then it dawned on me that I had an accident of that side of the car earlier and tempered glass is bad about creating microscoping stress fractures that can expand overtime and lead to the window shattering without warning. IKEA had this problem with tempered glass table tops getting small scratches in them and then one day just shattering all of a sudden. That's what tempered glass does.

    These sunroofs could develop small scratches from road debris (dirt, gravel, sand) and overtime they grow until the stress is relieved off the glass and it shatters.

  • sinenomine Nov 1, 2012

    Sunroofs - love 'em and hate 'em. If they don't explode they eventually leak or fail to operate. Mind you that doesn't keep me from having one in my car.

    General Motors offered sunroofs on a few Oldsmobiles, Buicks, and Cadillacs as long ago as the 1930s but then stopped making them for years. Those old cars with sunroofs are very rare now. Apparently they couldn't surmount the problems and maybe some car makers still can't.