The contact owns a 2015 Mercedes-Benz C300. The contact stated that while driving at approximately 70 MPH, there was a loud clicking sound coming from the panoramic sunroof. The contact stated that the sunroof then became inoperable. The contact became aware of NHTSA Campaign Numbers: 23V854000 (Structure) and 21V197000 (Structure). The dealer was contacted and confirmed that the VIN was not included in the recalls. The vehicle was not diagnosed or repaired. The manufacturer was informed of the failure and confirmed the VIN was not under recall. The manufacturer referred the contact to the NHTSA Hotline to report the failure. The failure mileage was 115,000.