I purchased a new GLS 450 less than 6 months ago. It now has 4600 miles. I was driving from Florida to Virginia when suddenly the sun roof exploded that sounded like a shotgun blast. Mercedes is providing a replacement sun roof glass under warranty, but my wife now refuses to drive the car fearing a recurrence. We have 3 young grand children who frequently ride in this car.
Has anyone experienced a similar incident and what was your thoughts relative to a possible recurrence?
I have asked MB to take the vehicle back using the cost formula for Lemon repurchases. Any suggestions to help me get this done, otherwise I will have to trade it on the open market and pay $$ thousands in penalty for the immediate depreciation.

 

Unfortunately, this is not unique to Mercedes. Even BMW has started doing away w/a moving pano roof and offering a fixed glass only option.
A panoramic roof that is also a moonroof is a nice feature but not worth the potential headache IMHO.

 

Exactly, this is a cross manufacture problem, from Mercedes-Benz, BMW, even Hyundais.

Trenton O. Gibson
tgibson@highline-autos.com
Highline Autos
Direct: 602.909.9216
Office: 480.348.0777

 

Welcome to the joys of owning a new GLS! The black glass panel between the windshield and sunroof exploded on my GLS nine months into my purchase. Of course MB said a pebble hit it and that it is not under warranty. There was a class action lawsuit against MB regarding your exact issue ... haven't checked on the status of the litigation recently though.

 

Was it the panel that moves or the rear panel that is fixed?

 

It was the front panel that opens

 

As others have said, if you google this it happens on a wide variety of cars. It’s not unique to MB as they don’t themselves manufacture glass. The glass in my Mercedes is made by Pilkington who makes glass for many many brands of vehicle.

Great that MB covered it under warranty they usually won’t.

 

Not unique to MB at all. My neighbor has a Tesla and this happened to him as well as well as my cousin who has a Porsche Macan. I personally have not had it so I am not sure how they will deal with it but I would assume running it through insurance is one option.

 

A rock hit to glass can sound like a shotgun blast, so it's difficult to ascertain whether a rock caused the breakage, or a defect.

If the dealer said it was an object, having checked other possibilities, it's likely the case. They would make money replacing it, and probably sublet the labor so as not to take up shop time.

Use their finding to support your insurance claim, if the insurer needs something. They will probably just accept it as a broken sunroof.

Regarding your wife's reluctance to keep the car, that's something that's real.
The likelihood of a recurrence is low, but if you don't trust the car, it diminishes it's value to you.

Hard choice.

 

Just Google this. Sunroofs explode all the time, they’re not caused by rocks hitting them they’re caused by flaws in the tempered glass that lay dormant for years and then give way. This happens with rear windows and side windows too but is most common with sunroofs and rear windows.

This happens with other types of tempered glass also. Just the other day one of the tempered glass doors in one of my offices exploded. Just sitting there nobody touching it.

The only way to avoid the possibility of this happening is to buy a car with no tempered glass which is basically impossible. The S Class has no tempered glass other than the panoramic roof but you can’t get one without the roof.

 

Rocks and other objects can cause either immediate damage, or delayed damage by initiating a stress riser that finally propagates.
It's always catastrophic because all the stress contained by the tempering process is released violently. The benefit is No Shards.

Current acoustic packages have laminated glass - I have had such in my last two SUVs.
It seems that it would be a safety improvement by containing occupants and resisting intrusion.
Emergency crews need different equipment and training to get through side glass for rescue.
(And me for exit, as this thread now reminds me.)

It's been standard on S Class since 2021. Optional on some other models.

 

Even with laminated glass most cars still have tempered rear windows. The downside is you can’t escape a car with laminated glass through the windows like you said.

 

Thanks for the detailed explanation, however in my case there might not have been shards, but there were chunks of glass larger than your hand. I found paint damage on left rear panel that was apparently caused by flying glass. I had the roof cover closed otherwise I believe it could have been catastrophic.

 

It’s still tempered glass. Sometimes it breaks off in shattered chunks but they still are blunt and won’t hurt you is the point. The flying glass will definitely cause paint damage. Even if your shade had been open you would have been okay. Would have been awful! But you would have been okay