The issue is regarding the “Traffic Sign Assist” (Owner’s Manual page 221) feature of the Adaptive Cruise Control System. Vehicle will be made available if requested. The function of the "Traffic Sign Assist" is to monitor roadside "Speed Limit" signs and the cruise control will increase or decrease speed to stay within the permissible legal speed limit. The system worked except occasionally it would change the indicated permissible speed limit on the instrument display when there is no corresponding roadside speed limit sign and the permissible speed limit for that stretch of roadway is unchanged. When this happens, suddenly and abruptly, the vehicle display would indicate a "phantom" Higher or Lower Speed Limit sign and rapidly and abruptly accelerate or decelerate. Again there were no roadside signs posted indicating a higher or lower speed limit! The risk is potential for rear end collisions from or to other traffic due to the abrupt acceleration or deceleration. when we returned home from a 4556 mile road trip, we took the vehicle to the Mercedes dealer for routine service and mentioned this to the Service Advisor. He indicated that when this defect is reported their solution is to deactivate the system. I don't feel this is adequate since another driver could reactivate the system through the settings. It has not been inspected by anyone except the dealer. There were no warning lamps, messages or other symptoms before the display changed and the vehicle abruptly accelerated or decelerated.

I purchased a new Mercedes Benz GLC300 2023. Last month, my friend and I were driving on I75 in Florida when we heard what sounded like a loud boom or gunshot. We quickly discovered that my sunroof had exploded. The sunroof was closed, and fortunately so was the sunshade, as large pieces of glass flew off the roof and smaller shards of glass collected on top of the sunshade. My friend and I were fortunate to have not been insured and were able to safely navigate the vehicle to the side of the road to assess the damage. In contacting the MB dealership, I learned that the sunroof is considered "glass" and thus not covered under warranty even though the vehicle is only 3 years old with less than 50,000 miles. What is more concerning to me is that the roof was not under a recall, and there have apparently been other MB owners that have experienced the same issue with class action lawsuits pending. My insurance company covered the repairs following payment for the deductible. This huge safety concern is that we could have been seriously injured by flying and/or falling glass. I write to express my deepest concern over the safety issue the exploding roof presents-the cost of repair relative to what could have happened is minor. Thank you for the attention to this matter.

The glass panel between the windshield and the sun roof shattered spontaneously

When loading groceries in my trunk, the door randomly closes on my head. The last time this door closed while we were loading, I tried stopping it with my hand, by holding it, so my spouse doesnt get smashed, and it will not stop at all. There needs to be a safety feature installed to stop this trunk from closing if a person is underneath it. I fear that a child or an elderly person wont be able to move fast enough and will be severely harmed by this.

The rear door randomly closes with force unexpectantly. We contacted the Mercedes dealer where the car was purchased and is serviced. They responded it can not be fixed and was an ongoing concern of many owners