My rear electric window is leaking into my back seat area and the ceiling of the truck has water stains. It is coming from the roof and is leaking in 3 different areas. I am afraid I will now have mold in my car and I can-??t have my grandchildren in the car to be safe for them. I had it checked at a local GMC dealer and I had to pay for a leak speacialist to verify and they confirmed the window has a leak. The leak started in April 2025 and has slowly gotten worse. The dealership said I will need to replace my back window to fix the issue and gave me an estimate of $1,100 and said my extended warranty will not cover this issue.

- Cincinnati, OH, USA

I don't believe this needs to have an investigation, but i would like it documented and brought to GM's attention for future body designs. I have never had as many rocks/debris hit my windshield as I have with this truck. I have had one chip in a windshield in 30+ years of driving, until this truck where I have had several that needed repairs, and this last one has created a Crack large enough where my windshield needs replaced. It may be bad luck, but I've talked to multiple other Sierra owners and most of them have had the same issue. A couple have had the windshield replaced almost yearly. Please at minimum inform GM engineers to possibly determine the cause (I assume aerodynamics) so they can incorporate the flaw (if there really is one) into future designs. The photo I included happened almost immediately after the impact. The crack has grown several inches since as expected.

- New Windsor, IL, USA

Wipers work intermittently

- Carolina, PR, USA

The wiper blade motor is defective. While driving during a storm the wiper blade motor stopped working on the delayed and low settings. This was a safety issue while driving. I took my vehicle to get looked at a GM Dealer to look at the vehicle. My vehicle is only 3 years old and should not have issues with the wiper blade motor.

- Beaufort, SC, USA

The driver-side mirror on my 2021 GMC sierra is unusable at freeway speed. When traveling at freeway speed the glass moves due to wind and causes the reflection in the mirror to be blurry. The reflection from the mirror is blurry to the point that I'm unable to identify objects in the mirror and it is difficult to gauge size and closing speed of any objects in the mirror. The issue has been with the vehicle since I purchased it new in June of 2021. The issue has been reproduced by two different dealership service centers and the entire driver-side mirror assembly has be replaced twice with the issue persisting. I have videos showing the issue but they are too large of files to upload on this form.

- Modesto, CA, USA

Sun glare reflects off center console cup holder with such intensity it's hard to Focus on the road even with sunglasses on.

- Travis Afb, CA, USA