What 7 owners told NHTSA about the 2025 Mercedes-benz GLS 450 4matic

We recently noticed visible damage to one of the seatbelts in our 2025 Mercedes-Benz GLS450. The affected component is the seatbelt webbing. The belt has visible fraying and pulled/cut fibers along the edge in two separate spots near the area where the belt retracts. The vehicle is very new, and the damage appears abnormal for a safety-related component. The damage is localized near the belt path/retractor area, and we are concerned it may be related to an issue with the seatbelt path, retractor mechanism, surrounding trim, alignment, or another defect in the restraint system. The component is available for inspection upon request. This creates a safety concern because the seatbelt is a critical occupant restraint system. If the webbing fibers are damaged, the seatbelt may not perform as intended in a crash or sudden stop. We are currently avoiding use of that seating position until the issue is inspected and resolved. The problem has been brought to the attention of a Mercedes-Benz dealer. The dealer quoted approximately $2,250 to replace the affected seatbelt and indicated that it would not be covered under warranty. To our knowledge, the dealer has not yet fully inspected the seatbelt mechanism, belt path, surrounding trim, or retractor area to determine whether the damage is related to a defect or abnormal condition in the vehicle. The vehicle/component has not yet been inspected by the manufacturer, police, insurance representatives, or an independent service center. We are requesting further inspection by Mercedes-Benz because this is a safety-related component on a new vehicle. There were no warning lights, dashboard messages, or other symptoms before we noticed the seatbelt webbing damage. The first symptom was the visible fraying/pulled or cut fibers on the seatbelt webbing. The exact cause is UNKNOWN.

NHTSA ODI 11747197

Brake pads completely worn after 11K miles - this seems like premature wear and like there is a potential issue with the braking system on the GLS450.

NHTSA ODI 11740240

Accident report: Local ID [XXX] Agency: ISPLowell 13 Date [XXX] Time approx [XXX] Milepost [XXX] on [XXX] Auto: 2025 Mercedes GLS 450 fully loaded Single car accident See attached pictures for damage State Farm insurance - claim filed (claim # [XXX]) Claim filed with Mercedes Benz on 3/9/2026 to access info from event data recorders (claim #[XXX])a total loss Driver’s 2 front airbags deployed - chest and legs. Driver was in left lane with no traffic around - slight drizzle Car started to move a bit in between the lane markers as if the lane assist was engage and trying to keep the car in the lane Driver had both hand in the wheel and was paying attention - tried to stabilize the wheel when all of a sudden the wheel turned hard left (driver couldn’t correct wheel) and drove the car starting into the cement center median. The car seemed to jump a bit and finally came to rest in the median (not touching the median) facing in the original direction at a slight angle to the left. Driver reports that it also seems the wheels may have locked up. Driver was driving a safe soled at 65 in a 70 zone and was fully attentive. Driver suspects the lane-assist feature. Fortunately, the driver was not seriously hurt - just a couple of bruises from the seat restraint system and the airbag deployment. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ODI 11723124

The contact owns a 2025 Mercedes-Benz GLS450 4Matic. The contact stated that while driving at various speeds, a safety feature with a white speed limit sign started flashing on the instrument cluster. The contact stated the flashing was a constant issue. The vehicle was taken to the local dealer several times. The contact was informed by the dealer that it was a known issue and that the manufacturer was still developing a fix. The vehicle was not repaired. The manufacturer was informed of the failure. The failure mileage was 5,265.

NHTSA ODI 11721777

I am writing to file a formal complaint regarding a serious malfunction of the Automatic Emergency Braking (AEB) system. This malfunction caused my vehicle to unexpectedly perform an emergency stop without a valid cause, resulting in significant damage to its suspension system. Incident Details: •Date of Incident: Friday, December 5, 2025, between 10:45 am and 11:15 am ET •Location: Community Baptist Church of Englewood, 224 1St, Englewood, New Jersey. •Description: While driving under normal conditions on a clear, dry road with no obstructions, the vehicle's AEB system engaged suddenly and forcefully. The abrupt, maximum-force braking caused severe stress and impact on the vehicle's suspension components, leading to a bent suspension linkage/component. The car is currently unsafe to drive. The damage to the suspension was not a result of normal wear and tear or an external impact caused by a collision. It was a direct consequence of a failure within a critical safety system designed and installed by Mercedes-Benz. An abrupt emergency stop due to a system malfunction places extreme, unintended stress on the vehicle's mechanical components, including the suspension and alignment systems. While Mercedes-Benz of Smithtown Service authorized the repair and will fully cover its cost, the reason was noted for to agreement was noted as “not to argue with a client who has a long-standing relationship with Mercedes-Benz.” I am asking for this to be officially reported as a defect for Mercedes-Benz to resolve in their design, which will safeguard all future and current drivers as well as the public.

NHTSA ODI 11703696

The contact owns a 2025 Mercedes-Benz GLS450. The contact stated that while driving approximately 50 MPH, a loud popping noise had occurred, and suddenly the panoramic glass sunroof exploded, causing shards of glass to fall into the cabin of the vehicle. During the incident, shards of glass contacted the driver, front seat passenger, and middle row passenger located on the driver's side. The driver sustained lacerations to the left hand and neck, which would require medical treatment. The children were traumatized by the event. The cause of the failure was not determined. The manufacturer and local dealer were notified of the failure. The failure mileage was 10,000.

NHTSA ODI 11699107

The contact owns a 2025 Mercedes-Benz GLS450 4Matic. The contact stated that while driving at an undisclosed speed, the engine overheated, with several unknown warning lights illuminated. The vehicle was taken to the dealer, where it was diagnosed that the coolant pump had failed and needed to be replaced. The vehicle was repaired. The contact then stated that while driving at an undisclosed speed, there was a metallic clicking sound was coming from the engine compartment, and there were no warning lights illuminated. The contact stated that the front of the vehicle near the instrument panel was very hot. The vehicle was taken back to the dealer, where it was not diagnosed or repaired. The manufacturer was made aware of the failure. The approximate failure mileage was 14,050. The VIN was not available.

NHTSA ODI 11692173