How to prevent car sunroofs from shattering spontaneously

Hundreds of complaints filed about the issue

(KPRC) It sounds like something out of a movie -- sunroofs that spontaneously explode, sending broken glass flying right at drivers.

But it's happening to hundreds of people.

[WEB EXTRA: Search federal complaints | File a complaint]

It was a routine drive to work for Wade Owens until he heard the sound.

"It sound like something exploded," Owens said.

Owens said small pieces of glass came raining into his car and his eyes. The sunroof on his 2013 Kia Sportage had shattered -- a scary experience, but not an isolated one.

Ayesha Farr was driving her 2013 Kia Optima home from work when she heard the sound.

"I mean, literally sounded like a gunshot. I was scared because I thought someone was shooting on the highway," Farr said.

There are hundreds of complaints to the National Highway Traffic Safety Administration about the problem, including several from Florida Local 6 found on the website that date back to 2009.

Car makers Audi and Hyundai both issued voluntary recalls on some models because of the issue. But as drivers call other car manufacturers, like Kia, to report what NHTSA has named "spontaneous sunroof breakage," the company blamed "external impacts from rocks or other foreign objects."

"I'm 100 percent sure that it wasn't a rock," Owens said.

"They're not taking responsibility because they've had to make the cars lighter," said Donald Phillips, an engineer who consults in accident investigations and specializes in auto glass.

Phillips said there are several factors resulting in so many fractured and faulty sunroofs in recent model years.

"The main issue is that the glass in the structure around the sunroof is being made thinner in vehicles," Phillips said.

He said car makers are under pressure from the federal government to make vehicles with better fuel mileage, and they're doing that by using lighter metals for the frame and auto bodies.

"The problem is that going with the thinner materials and the thinner metal in the cars, you're getting more movement, so now you're more on the edge of what they used to be, when things were heavier and thicker and more robust," he said.

Kia's own investigation found no evidence of a defect, but federal regulators opened their own investigation, noting that the rate of reported incidents is concerning. The investigation that started in May 2014 is still open, but even without your car's manufacturer issuing a recall, Phillips said there are some things consumers can do.

When it's really hot out and you're not in the car, leave the shade to your sunroof open so heat doesn't build up between the glass and the shade, putting more pressure on the glass. Getting your sunroof tinted on the inside will prevent glass from showering down on you if the sunroof does break.

You can search for your car's make and model in NHTSA's database online to find out how many times others have complained about this issue happening in the car you drive.