2015 Mercedes-Benz C 300 Body & structure Problems

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 manufacturer was notified of the failure and informed the contact that the dealer was unreachable. The failure mileage was approximately 120,000.

NHTSA ID

11754977

Incident

Jul 15, 2026

Mileage

120,000 mi

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.

NHTSA ID

11733048

Incident

Apr 17, 2026

Mileage

62,612 mi

The contact owns a 2015 Mercedes-Benz C300. While driving approximately 15 MPH, the brake pedal was depressed, and the body of the vehicle shifted to one side. The vehicle was drivable after the failure. There was no warning light illuminated. The vehicle was driven to the residence and parked. The contact stated that due to the failure, the vehicle was unsafe to drive. An independent mechanic was contacted, and it was determined that the rear subframe was corroded. The vehicle was not repaired. The manufacturer was notified of the failure, and it was confirmed that the VIN was not under recall. The failure mileage was not available.

NHTSA ID

11722220

Incident

Feb 16, 2026

Rear subframe rusted out, car is not safe to drive

NHTSA ID

11698179

Incident

Oct 23, 2025

I’m the owner of a Mercedes Benz C- Class Sedan 2015. My Rear Sub Frame Rusted Through at The right trailing arm - Fails state inspection. Mercedes Benz has issued a extended 20 year warranty on all vehicles from 2008 - 2015 C - Class Sedan for Rear Sub Frame that rusted out. Mercedes Benz service advisor stated that my vehicle was not under that extended warranty when he run my vehicle Vin number. My vehicle should be under that warranty, I have the same problem with the same vehicles on the list. Please help. Thank you

NHTSA ID

11695279

Incident

Oct 23, 2025

The contact owns a 2015 Mercedes-Benz C300. The contact stated that upon taking the vehicle for the State Inspection, the contact was informed that the rear subframe was rusted, and there was a hole on each side of the rear subframe. The vehicle was taken to the dealer, where an unknown diagnosis was made, and the dealer ordered an unknown part to repair the vehicle. The vehicle was not repaired. The manufacturer was notified of the failure but denied assistance. The contact was referred to the NHTSA Hotline for assistance. The failure mileage was approximately 60,000.

NHTSA ID

11681594

Incident

Aug 19, 2025

Mileage

60,000 mi

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.

NHTSA ID

11671701

Incident

Apr 2, 2025

Mileage

110,000 mi

The contact owns a 2015 Mercedes-Benz C300. The contact stated that while his wife was driving at an undisclosed speed, the roof panel detached from the vehicle and fractured. The contact stated that the roof panel had previously been replaced, but the failure occurred. The vehicle was taken to the dealer, where it was determined that the front roof panel needed to be replaced. The vehicle was not repaired. The contact related the failure to NHTSA Campaign Number: 23V854000 (Structure); however, the VIN was not included in the recall. The manufacturer was made aware of the failure. The failure mileage was approximately 70,000.

NHTSA ID

11669469

Incident

Jun 26, 2025

Mileage

70,000 mi

The contact owns a 2015 Mercedes-Benz C300. The contact stated that while driving at 50 MPH and attempting to decelerate, the front end of the vehicle began to drift to the right while the rear drifted to the left. The vehicle returned to normal functionality, but the failure became a regular occurrence. No warning lights were illuminated. The vehicle was taken to the dealer, who diagnosed a failure with the rear subframe. The vehicle was not repaired. The manufacturer was notified of the failure and referred the contact to the NHTSA Hotline for assistance. The failure mileage was 136,000.

NHTSA ID

11653394

Incident

Apr 4, 2025

Mileage

136,000 mi

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.

NHTSA ID

11648819

Incident

Mar 12, 2025

Mileage

115,000 mi

I took my vehicle to an independent repair shop for routine maintenance and while there I was advised that the vehicle is suffering from the subframe corrosion issue. I called the manufacturer service center and they took my VIN and said I was not covered under the bulletin. The independent contractor gave me an estimate to get it repaired, however Mercedes doesn’t even have the parts needed in stock as they are backed ordered nation wide. This is our only car and it now I am forced to drive an unsafe vehicle.

NHTSA ID

11648255

Incident

Mar 13, 2025

I had the sunroof opened and it almost blew off, if I didn’t pull over it would have. I took it to the shop and was told it is a manufacturers issue.

NHTSA ID

11646561

Incident

Sep 12, 2024

The contact owns a 2015 Mercedes-Benz C300. The contact stated that while driving at various speeds, there was a sound of air entering the vehicle from the sunroof. No warning lights were illuminated. The vehicle was taken to a local dealer to be diagnosed. The contact was informed that the entire roof lining needed to be replaced. The vehicle was not repaired. The contact linked the failure to NHTSA Campaign Numbers: 23V854000 (STUCTURE), and 21V197000 (STRUCTURE); however, the VIN was not included. The manufacturer was notified of the failure. The approximate failure mileage was 50,000.

NHTSA ID

11629702

Incident

Feb 9, 2022

Mileage

50,000 mi

I believe my car was missed on the panoramic roof issue. I have been hearing a lot of wind and road noise coming into my car from the roof and now my roof is having issues completely closing. A few guys with c300 I know were recalled for the same issue and they had theirs repaired from the dealer under recall and after a few trips to different dealers they told me to try and add it here through the website.

NHTSA ID

11617653

Incident

Aug 5, 2024

My car (vin [XXX] ) a 2015 Mercedes C300 is experiencing the same premature rusting on the subframe. I was told that while a lot of Mercedes are covered, mine is not for some reason but I'm at the same risk for the subframe getting holes in it and wheels breaking off. I only have 78,000 miles on my car, only have it serviced at the dealer and it has been garaged parked. This type of damage is not typical for a car that has been this well cared for and for the amount it has been driven. I called Mercedes to honor the $5600 or to extend the warranty should it have to be replaced and they said to file a claim here. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

NHTSA ID

11610913

Incident

Aug 26, 2024

The rear subframe is rusted through. It is a known manufacturing defect where water sits and rusts through the subframe. This was a recall on various Mercedes up through 2014. Multiple 2015 models have the same issue, including my Mercedes 2015 C300 4MATIC. I have a 2009 SLK with the same issue, which Mercedes previously fixed and acknowledged the manufacturing defect. The part number under the recall through 2014 is "212 250 3805" My 2015 car has part number "212 350 3605" that is not covered but still has rust issues. See attached picture The subframe can result in the back wheels falling off. My subframe is severely rusted through and a risk as a driver. A certified Mercedes dealer has inspected this issue and confirmed the safety but Mercedes will not cover the repairs for the known defect. There are no warning lights or indicators to this issue.

NHTSA ID

11608926

Incident

Aug 16, 2024

SUNROOF SLIDE AND SHOE REPAIR. SLIDES HAVE MELTED DUE TO HIGH TEMPERTURES OWNER OPERATIOR DID NOT CAUSE ISSUE. Opened sunroof and sunroof would not closed. Discovered melted slides inside to sunroof tracks. It was a Rainy day and could not get sunroof to closed. Would have interfered with the visibility to drive due to water getting inside vehicle. Cost to repair is extremely high for this repair and when contacting repair shops they are seeing a large number of Mercedes with the same problem.

NHTSA ID

11598380

Incident

Jun 23, 2024

The contact owns a 2015 Mercedes-Benz C300. The contact stated while washing the vehicle, he observed that the roof panel had become detached. No warning lights were illuminated. The vehicle was not taken to the dealer or an independent mechanic. The vehicle was not repaired. After investigating the failure, the contact related the failure to NHTSA Campaign Number: 21V197000 (Structure), but the VIN was not included. The manufacturer was notified of the failure but referred the contact to the NHTSA Hotline for assistance. The failure mileage was 90,000.

NHTSA ID

11593757

Incident

Jun 11, 2024

Mileage

90,000 mi

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.

NHTSA ID

11592633

Incident

Mar 4, 2024

Mileage

103,000 mi

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 was informed that the repair could not be covered under warranty. The failure mileage was approximately 103,000.

NHTSA ID

11580056

Incident

Jul 1, 2023

Mileage

103,000 mi

My wife and I were driving our 2015 C-Class Mercedes on a highway, traveling at roughly 55MPH on 2/25/24, at approximately 2pm, conditions were sunny but windy, when suddenly we heard a loud noise above our heads. The noise sounded like it came from around our sunroof, and it sounded as if maybe the car had been hit by a piece of debris, although neither of us saw anything. We looked in our mirrors but didn't see anything, and I also tried opening and closing the sunroof and it worked fine. I also looked in my rear view mirror and didn't see any cars behind me swerve, or in any way adjust their driving. Because there was no safe shoulder on that part of the road, we continued a mile or so further up the road and then pulled over to see if we could visibly see anything wrong with the car. To our disbelief, a section of the body of the car that is just above the front windshield and just before the sunroof, a piece I believe called the "front stationary sunroof panel" , was completely missing! We were unsuccessful at finding the piece. After some research in recent days, I believe this issue is related to MB recall campaign #2021070010, 22V-954 / 2023010004/5/6. If this is however related to the recall, the Mercedes dealership we took our car to on 3/1/24 told us it would cost us over $2,000.00 to repair. As I thought about a piece of the car simply flying off while driving, I realized how much of a safety hazard this could pose to others, hence this written report.

NHTSA ID

11576462

Incident

Feb 25, 2024

The contact owns a 2015 Mercedes-Benz C300. The contact stated that the vehicle was taken to a dealer for routine maintenance and was informed that the rear sub frame was rusted and needed to be replaced. No warning light was illuminated. The vehicle was not repaired due to the cost. The manufacturer was made aware of the failure and referred the contact to the NHTSA Hotline. The approximate failure mileage was 93,000.

NHTSA ID

11574879

Incident

Jan 26, 2024

Mileage

93,000 mi

The contact owns a 2015 Mercedes-Benz C300. The contact stated that while the vehicle was at the dealer for routine service, a corrosion inspection was performed. The contact was informed of a rust hole in the sub frame. The vehicle was not repaired. The manufacturer was made aware of the failure and advised the contact to report the failure to the NHTSA Hotline. The failure mileage was approximately 76,000.

NHTSA ID

11567800

Incident

Sep 25, 2023

Mileage

76,000 mi

I have a 2015 Mercedes-Benz C300 4Matic got a letter from the company car had few recalls to address. Dropped the at Mercedes-Benz Hampton VA dealership on 12/06/2023 at 8:30 AM EST. After few hours got a call from the dealership that rear subframe of the has bad corrosion and because of the rust it got holes in it which is a bad safety risk. Risk is so great that it cant pass Virginia state inspection. I did a good online research and found it is a common issue in Mercedes-Benz vehicles and the company issued safety recall on some years and models but not on all the affected vehicles. Like my car has the exact same safety issue rear subframe got rust from inside so it was hard to notice till it became unsafe to drive the car. The dealer is asking almost $5000.00 to replace it. The Mercedes-Benz customer support center is unable to explain why some cars are covered with extended warranty offered by the factory and some doesn't for exact same issue. There are bunch of more people with same complaint but they don't know where to go.

NHTSA ID

11559001

Incident

Dec 6, 2023

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.

NHTSA ID

11537283

Incident

Aug 7, 2023

Mileage

100,000 mi