Which parts fail
Components named in complaints (doors, hood, frame, rust, paint and trim).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2015 Mercedes-Benz C300 owners, lightly cleaned up (personal details are redacted by NHTSA).
The contact owns a 2015 Mercedes-Benz C300. The contact stated while driving 50 MPH, the contact heard an abnormal flapping sound coming from the opened panoramic moon roof. The contact reached up into the open moon roof and discovered that the adhesive bonding on the front panel had started to deteriorate. The contact took the vehicle to the local dealer and was confirmed the failure however, the contact was informed that the dealer was not equipped to perform the repair. The contact was referred to Mercedes-Benz of Wilkes-Barre (150 Motorworld Dr, Wilkes-Barre, PA 18702) where the mechanic removed the bonded panel and installed a new front panel which the contact paid for out of pocket. The first dealer then notified the contact of NHTSA Campaign Number: 21V197000 (Structure) and instructed him to call the dealer where the vehicle was repaired. …
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 drive. The contact was provided an estimate for the repair and was informed that goodwill assistance would not be provided. The vehicle was not repaired due to the cost. …
The contact owns a 2015 Mercedes-Benz C300. The contact stated that while his girlfriend was driving at an undisclosed speed, the brake pedal was depressed; however, the vehicle failed to stop as intended. The vehicle independently pulled to the left and crossed the yellow line into the direction of oncoming traffic. The vehicle was almost involved in a head-on collision due to the failure. The vehicle was taken to the dealer, however the vehicle was not diagnosed or repaired. The contact was informed that the repair would not be covered under warranty. The vehicle was taken to an independent mechanic where the vehicle was diagnosed with a fractured subframe and that the subframe needed to be replaced. The vehicle was repaired. The manufacturer was made aware of the failure and advised the contact to report the failure to the NHTSA Hotline. …
The contact owns a 2015 Mercedes-Benz C300. The contact stated while driving 45 MPH, the roof carriage started shuddering. The contact veered to the side of the road. Upon inspecting the vehicle, the contact noticed that the roof panel had loosened. The contact stated continued driving and the roof panel fractured and partially separated from the vehicle. The vehicle was taken to an auto glass repair shop, where the roof panel was replaced; however, the failure reoccurred. The vehicle was taken back to the same auto glass repair center. The contact then became aware of NHTSA Campaign Number: 21V197000 (Structure) that he related to the failure. The dealer and the manufacturer were notified of the failure and informed the contact that the VIN was not included in the recall. The vehicle was not repaired. The failure mileage was approximately 85,000.
The contact owns a 2015 Mercedes-Benz C300. The contact stated that upon taking the vehicle to an independent mechanic for a routine maintenance check, the contact was informed that there was severe corrosion on the subframe of the vehicle. The contact was informed that the vehicle was unsafe to drive and that several failures might occur due to the failure. The contact stated that recently, while depressing the brake pedal, the vehicle swerved, and the contact lost control of the vehicle. Upon investigation, the contact discovered that there was a warranty on the vehicle related to the failure. The manufacturer was notified of the failure, and the contact was informed that the vehicle was no longer covered under the warranty. The vehicle was not repaired. The failure mileage was approximately 110,000.
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 was made aware of the failure but provided no assistance. The failure mileage was approximately 62,612.
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 failure mileage was approximately 120,000.
The contact owns a 2015 Mercedes-Benz C300. The contact received notification of NHTSA Campaign Number: 23V854000 (Structure) however, the part to do the recall repair was not yet available. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The contact stated while driving 50 MPH, the panoramic plastic piece suddenly detached from the vehicle. The location where the piece was attached was fractured allowing wind and water to leak inside the vehicle. The dealer was contacted. The manufacturer was made aware of the issue. The manufacturer referred the contact to the NHTSA Hotline to report the failure. The failure mileage was 103,000. VIN tool confirms parts not available.
The contact owns a 2015 Mercedes-Benz C300. While the contact's 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 manufacturer's extended warranty coverage for the failure. The failure mileage was 110,000.
The contact owns a 2015 Mercedes-Benz C300. The contact stated while driving at approximately 65 MPH, she heard a rushing air sound as if the sunroof was opened; however, the sunroof was not open. The contact stated that when she reached her destination, she noticed there was a panel missing from the roof between the sunroof and the windshield. The contact had not taken the vehicle to a local dealer or independent mechanic. The vehicle had not been diagnosed or repaired. The manufacturer had been informed of the failure. The contact researched online and related the failure to NHTSA Campaign Number: 21V197000 (Structure). The failure mileage was approximately 100,000.
Related recalls
Structure › Body › Roof and pillars
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2014-2020 C-Class, CLA, GLA, S-Class, GLC, and GLE vehicles. Please refer to MBUSA's recall report for specific vehicle details. The front roof panel located between the windshield and the panoramic sunroof may not have been bonded correctly to the vehicle during a prior…
Remedy: Dealers will replace the front panel, free of charge. Owner notification letters were mailed on August 2, 2024. Owner notification letters will be mailed in phases, on, March 22,2024, and August 2, 2024.
Structure › Body › Roof and pillars
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2017-2020 C300 Coupe, C43 Coupe AMG, C43 AMG, 2015-2020 C300, GLA250, 2016-2018 C350e, CLA45 Coupe AMG, 2015 C400, S65 AMG, 2015-2019 C63 AMG, 2016 C450, 2015-2016 GLA45 AMG, S600, 2016-2020 GLC300, 2017-2019 GLC43 AMG, GLE43 Coupe AMG, 2014-2019 CLA250 Coupe, 2014-2015 CLA45…
Remedy: Mercedes-Benz dealer will remove the bonded panel and will install a new front panel by following the detailed repair instructions and using the approved primer, cleaner and adhesive, free of charge.
NHTSA investigations
Front Roof Panel Detachment
On January 8, 2021, after ongoing review with Mercedes Benz, the National Highway Traffic Safety Administration (NHTSA) Office of Defects Investigation (ODI) opened PE21-001 to assess allegations of front roof panel detachments while driving at highway speeds in certain 2015 Mercedes-Benz (Mercedes) C-Class vehicles.The subject front roof panel is a stationary panel composed of polycarbonate and is attached to the…
Body complaints in other C300 years
Frequently asked questions
How common are body problems on the 2015 Mercedes-Benz C300?
NHTSA has 60 complaints about the body & structure of the 2015 Mercedes-Benz C300, 16% of the model year's 381 complaints. The component named most often is body (33 mentions).
Is there a recall for 2015 Mercedes-Benz C300 body problems?
Yes — NHTSA recall 23V-854 (roof and pillars, Dec 15, 2023); NHTSA recall 21V-197 (roof and pillars, Mar 19, 2021). Recall repairs are free at authorized dealers.
At what mileage do 2015 Mercedes-Benz C300 body problems start?
Half of the complaints with a recorded mileage happened before about 63,000 miles, and 13% before 25,000 miles.
Is it dangerous?
Owners linked 1 crash, 0 fires and 0 injuries to body & structure problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.