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 2017 Mercedes-Benz C300 owners, lightly cleaned up (personal details are redacted by NHTSA).
The contact owns a 2017 Mercedes-Benz C300. The contact stated that while driving 65 MPH on the highway, the contact heard a popping sound coming from an unknown part of the vehicle. The contact pulled over to the side of the road, exited the vehicle, and became aware that the roof panel had shuddered. The contact stated there was no glass in the vehicle. No injuries were sustained. The contact stated that the failure had occurred on two occasions. The vehicle was not taken to an independent mechanic or the dealer to be diagnosed. The vehicle was taken to the dealer by the previous owner to be repaired under NHTSA Campaign Number: 21V197000 (STRUCTURE); however, the recall repair failed to prevent the failure. The manufacturer was notified of the failure and informed the contact that there was no recall related to the failure. …
The contact owns 2017 Mercedes-Benz C300. The contact stated while driving 45 MPH, he heard air coming in through the OSI cover. Once the contact arrived at his destination, he noticed that the front sunroof panel had detached from the vehicle. The dealer was contacted and stated that the vehicle was not under warranty and that the vehicle was already repaired under NHTSA Campaign Number: 21V197000 (Structure). The manufacturer was contacted and stated that the vehicle was not under warranty and that the dealer was not obligated to repair the vehicle free of changer. The failure mileage was 40,000.
The contact owns a 2017 Mercedes-Benz C300. The contact stated that while driving at 60 MPH, the contact became aware that an unknown part had detached from the vehicle. The contact stated that after stopping to refuel the vehicle, it was discovered that the roof panel was missing. The vehicle was not diagnosed or repaired by an independent mechanic or dealer. The contact related the failure to NHTSA Campaign Number: 23V854000 (Structure); however, the VIN was not included in the recall. The manufacturer was not made aware of the failure. The failure mileage was approximately 129,000.
The contact owns a 2017 Mercedes-Benz C300. The contact stated while driving 75 MPH, the front roof panel located between the windshield and the panoramic sunroof detached and flew off the vehicle. The vehicle was taken to the dealer and the contact stated that the vehicle had experienced the failure listed in NHTSA Campaign Number: 21V197000 (Structure) however, the VIN was not included in the recall. The vehicle was not repaired. The manufacturer was contacted, and a case was filed. The failure mileage was 41,700.
The contact owns a 2017 Mercedes-Benz C300. The contact received notification of NHTSA Campaign Number: 21V197000 (Structure) however, the part to do the recall repair was unavailable. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The manufacturer was made aware of the issue. The contact stated while driving approximately 60 MPH, the sunroof panel detached from the vehicle. The approximate failure mileage was 39,000. Parts distribution disconnect.
Basically, this is a common problem with the c300 coupes, I had an recall to replace front stationary sunroof panel. My sunroof panel started lift the last few months in 2022, therefore I took it to the dealership at the start of 2023 which they notified me this was a big problem and was unsafe on the road because it will eventually lift off while driving. Sense my engine lights were on and needed immediate attention, I had my car service which cost a lit of money. I had one problem about why would I be charged $400 for windshield seal which I assume was apart of the problem with sunroof panel seal. After car was in shop for quite some time, they fixed my sunroof panel that had an recall. About a month later, the sunroof panel was lifted and started to come off. I brought the car back into service which service advisor notified that he ordered about sunroof panel. …
I am reporting a serious vehicle safety hazard caused by improper and unsafe repair work performed by USA Platinum Motor, located at 1221 California Lane #126B, Arlington, TX. I brought my 2017 Mercedes-Benz C300 in for a cold start rattle with no warning lights or prior issues. The shop diagnosed a loose timing chain and I authorized the repair. After the repairs, the vehicle was returned with critical safety defects, including a loose fuel pump, unsecured fuel line, missing bolts, and improperly reassembled engine components. Shortly after pickup, the car experienced loss of acceleration on the interstate, a strong odor of fuel, and a sudden loss of power, creating a dangerous and life-threatening situation. The vehicle had to be towed back to the shop. The manager, who is not a certified mechanic, admitted he personally "fixed" the issue by tightening the fuel pump himself. …
Repeated Panoramic Sunroof failure: sun roof rails are have been reported by the dealer to fail / crack and allow panoramic sun roof to dislodge from tracks securing this structure to the vehicle. NOTE THIS IS NOT RELATED TO/ADDRESSED BY THE PREVIOUS RECALL Loud cracking noises heard and the sunroof stuck in an open position and appeared at risk of departing the vehicle on initial occurrence 2019/2020 Dealer attempts to repair resulted in replacement of the rails which are reportedly "made of plastic and do not hold up well in southwestern US temperatures/climate" Repairs/rigging the system appears to "load the rails" and dealer reported life limits can be as low as 10 cycles / 30 months This issue has occurred three times in the past 4 years 92k miles Improper closure/ cracked tracks could result in incomplete cabin security during a roll over and/or potential for the panoramic sunroof …
The sunroof exploded spontaneously while driving to a destination. When the incident happened, I was stopped at a red light. I panicked as it sounded like gunshots hitting my car. I pulled over to the nearest safest destination to inspect the car. This put the safety of myself at risk and others at risk who were driving along the sides and/or behind me. This incident was confirmed by a dealer, as I went to Mercedes Benz Sugar Land on the following day of the incident and was quoted around $3,700 to have it repaired. The vehicle not been inspected by police and/or insurance. There were no warning signs that this could have happened besides the fact that Mercedes Benz USA is currently under an active lawsuit for this happening to several other drivers. …
The contact owns a 2017 Mercedes-Benz C300. The contact stated that while driving 60-65 MPH, the vehicle made an abnormal whistling sound. Additionally, the contact stated that while the vehicle was at the car wash, and she became aware that water was leaking inside the vehicle through the windshield bonded panel. An independent mechanic was contacted and informed the contact that the front windshield bonded panel could have detached; however, the vehicle was not diagnosed nor repaired. The dealer was not notified of the failure. The contact related the failure to NHTSA Campaign Number: 21V197000 (Structure); however, the VIN was not included. The manufacturer was notified of the failure and informed the contact that they could not assist because the VIN was not included in the recall. The failure mileage was unknown.
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.
Structure › Body
Mercedes-Benz USA, LLC (MBUSA) is recalling certain 2017-2018 Mercedes C300 Cabriolet, C300 4Matic Cabriolet, C43 AMG Cabriolet, C63S AMG Cabriolet, and C63 AMG Cabriolet vehicles. Due to a bonding issue introduced in the production process, the rear beltline trim may separate from the vehicle.
Remedy: MBUSA will notify owners, and dealers will inspect the rear beltline trim and replace the trim if necessary, free of charge. The recall began on September 21, 2018.
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 2017 Mercedes-Benz C300?
NHTSA has 24 complaints about the body & structure of the 2017 Mercedes-Benz C300, 11% of the model year's 216 complaints. The component named most often is body (18 mentions).
Is there a recall for 2017 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); NHTSA recall 18V-456 (body, Jul 10, 2018). Recall repairs are free at authorized dealers.
At what mileage do 2017 Mercedes-Benz C300 body problems start?
Half of the complaints with a recorded mileage happened before about 40,000 miles, and 33% before 25,000 miles.
Is it dangerous?
Owners linked 2 crashes, 0 fires and 2 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.