*Median odometer reading when the problem happened, where owners gave one. One complaint can name several problem areas.
Structure
The contact owns a 2015 Mercedes-Benz C300. The contact stated that while driving at an undisclosed speed, there was an abnormal sound coming from the vehicle and the vehicle became difficult to maneuver. The failure had occurred on several occasions. The vehicle was taken to an independent mechanic where it was diagnosed that there was two large holes and rust located on the rear subframe, an unknown part needed to be realigned and needed to be replaced. The vehicle was towed to a dealer where it was confirmed that the rear subframe and another unknown part needed to be replaced. The manufacturer was notified of the failure by phone and stated that the vehicle was not under warranty. The…
Jul 23, 2026 · 120,000 milesStructure
The contact owns a 2015 Mercedes-Benz C300. While the contactâs son was driving approximately 20 MPH, the vehicle veered to the left and into the next lane when the brake pedal was depressed. The vehicle was cautiously driven back to the residence and parked. The vehicle was later towed to the local dealer to be diagnosed, and it was determined that the rear subframe had severe rust and was fractured and needed to be replaced. The vehicle was not yet repaired. The manufacturer was notified of the failure, but no assistance was provided. The contact was informed that the vehicle was not covered under the manufacturerâs extended warranty coverage for the failure. The failure mileage was…
Sep 1, 2026 · 110,000 milesStructure
The contact owns a 2015 Mercedes-Benz C300. The contact stated that while driving at various speeds and depressing the brake pedal, the vehicle fishtailed on several occasions. The vehicle was taken to an independent mechanic, where it was raised on a lift, and the mechanic discovered that the rear subframe was severely corroded. The mechanic determined that the failure was associated with Manufacturer Communication Number: MC-10232321 (Structure); and referred the contact to a dealer for assistance. The vehicle was towed to the dealer, where the failure was confirmed, and it was discovered that the rear subframe had separated. The dealer informed the contact that the vehicle was unsafe to…
Jul 15, 2026 · 120,000 milesVisibility › Sun/moon roof assembly
The contact owns a 2015 Mercedes-Benz C300. The contact stated that while the vehicle was parked, the contact became aware that the panoramic roof failed to close as intended. The vehicle was taken to the dealer, where it was determined that the panoramic roof guide rails had failed. The contact was informed that the panoramic roof guide rails needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure, and a case was filed. The contact was informed that the mileage and age of the vehicle had exceeded the limitation. The failure mileage was approximately 110,000.
Apr 15, 2026 · 110,000 milesSuspension
Rear subframe rust has deemed the car unsafe to drive. Hitting a pot hole at high speed or any sudden stop could cause the subframe to collapse causing loss of control of car. Car is available for inspection upon request. Car was taken in for regular oil change and multi-point inspection when rust was noticed by mechanic at the dealership. Car is located in East TN not the snow belt. There have been recalls on similar models for the year prior, but this vin is not part of the recall and has same issue, although the number 204 which is part of the recall is stamped on the part. (Pic attached below.)
Jul 2, 2026Service brakes
The contact owns a 2015 Mercedes C300. The contact stated that the driver's side rear brakes and rotors were rusted. The contact stated that when the brakes were applied, they were slow to respond. The TPMS warning light was illuminated. The vehicle was taken to a braking center, which declined the warranty for the aftermarket parts. The local dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was not notified. The approximate failure mileage was 176,000.
Apr 1, 2026 · 176,000 milesSteeringCrash1 injury
I was driving my car was sputtering or trying to shut off while I press the gas and I let go of the gas and it catches and stayed on. I took it to the dealership and they said they found nothing wrong. May 3rd around 12pm im driving on the freeway and as im getting on the express lane going 60 it dies and I couldn't move the steering wheel and I slammed into a guardrail. After doing research my car (vin [XXX] ) had multiple recals from the fuel pump and steering wheel and the dealership never fixed or checked any recalls before selling it to me. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)
May 3, 2026Structure
The contact owns a 2015 Mercedes-Benz C300. The contact stated that while driving at an undisclosed speed, there was an abnormal sound coming from the vehicle. The vehicle was driven to the shoulder of the road. The contact inspected the exterior of the vehicle and became aware that the moon roof panel had detached, and the moon roof panel flew off the vehicle. The dealer was made aware of the failure. The contact stated that the vehicle was previously repaired under NHTSA Campaign Number: 21V197000 (Structure) in 2021. The contact was informed that the repair was not covered under warranty. The vehicle was not diagnosed or repaired by an independent mechanic or the dealer. The manufacturer…
Apr 17, 2026 · 62,612 miles
Owner complaints are submitted to NHTSA by the public and are not verified. Shown as filed (NHTSA removes personal details); long reports are shortened.