2021 MERCEDES-BENZ C 300 — Complaint #2168294
Open-data reference.
NHTSA Complaint about VISIBILITY:SUN/MOON ROOF ASSEMBLY filed January 20, 2026
NHTSA complaint #2168294 (ODI reference 11712287) concerns a 2021 MERCEDES-BENZ C 300 and was filed on January 20, 2026. The owner reports the failure occurred on October 6, 2025. The report was geocoded to California based on the filer's self-reported location. The affected component is categorized as visibility:sun/moon roof assembly, one of NHTSA's standardized taxonomy codes used to group defect patterns across make, model, and year.
The filer flagged the following severity indicators: crash: no, fire: no, injuries: 0, fatalities: 0. No crash, fire, or fatality was associated with this report, which places it in the early-warning stream rather than the priority-review stream. Because a VIN was supplied, this complaint is tied to a specific vehicle and not just a model-year cohort.
Individual complaints are consumer-submitted and unverified by NHTSA engineers — the agency's role at this stage is to collect, index, and make them searchable. What matters for federal action is the pattern: when many owners of the same MERCEDES-BENZ C 300 cohort independently describe similar visibility:sun/moon roof assembly failures, defect investigators have grounds to open a PE and request manufacturer data. Related filings for the same vehicle and component appear below, and the detail page for the full 2021 MERCEDES-BENZ C 300 shows the complete component-level complaint distribution alongside any active investigations or recalls.
Complaint Description
I am reporting a safety defect involving the panoramic sunroof on my 2021Mercedes-Benz Coop vehicle. The panoramic sunroof has malfunctioned due to an apparent design or manufacturing defect. The sunroof fails to open / close and makes grinding or popping noises which malfunctioned unexpectedly. This issue occurred without misuse and during normal operation of the vehicle. The defect creates a safety concern because it can distract the driver, allow water intrusion that may affect electrical components, and/or cause sudden glass or mechanical failure while driving. The vehicle has been taken to a Mercedes-Benz dealership for diagnosis and the issue was not resolved due to denied coverage. I was informed that the repair would be costly despite the issue appearing to be a known defect in Mercedes-Benz panoramic sunroof systems. I believe this defect may affect other Mercedes-Benz vehicles with panoramic sunroofs and should be investigated for a potential safety defect or recall.
Complaint Details
| NHTSA Complaint ID | 2168294 |
| ODI Number | 11712287 |
| Date Filed | January 20, 2026 |
| Failure Date | October 6, 2025 |
| VIN | W1kwj8dbxmg |
Source: NHTSA Vehicle Complaints Database. Component taxonomy and severity codes are standardized by NHTSA Office of Defects Investigation.
Read our methodology — how this data is sourced, computed, and verified.