A new Consumer Reports investigation says the problem is more common than first thought.
The group says the National Highway Transportation Safety Administration received at least 859 complaints over the last two decades, and most complaints are from the last few years.
They say part of the problem could be the type of glass in sunroofs.
Sunroofs are often made with tempered glass, not laminated glass.
"The glass in these sunroofs is not what's being used in your windshield, where if a rock hits it, it doesn't shatter,” said David Friedman with the Consumer's Union.
KIRO-TV's Jesse Jones investigated the problem in 2015. He spoke with a man, Tyler Moody, who was driving when his sunroof exploded.
“I literally thought there was a gunshot,” Moody recalled. “Glass just shattered. The front right here kind of fell down and hit me in the head.”
Mood is one of many people who’ve had the sunroof of their Hyundai Veloster shatter spontaneously.
Currently, Hyundai tops the list of vehicles with complaints. Ford and Nissan round out the top three.
Consumer Reports found many complaints involve sunroofs that cover a vehicle's entire roof.
There have only been minor injuries with the shattered sunroofs, but experts think more needs to be done to make sure vehicles are safe.