First, thank you to everyone who has described in this thread their sad experiences with this C-Class design fault. Recently my wife and I joined your ranks. We purchased our 2010 C300 4Matic new from a dealership and have had all of our services completed, on time, by that dealership. My wife has been the primary driver and has meticulously kept the car washed on a very regular basis. Until now this car has been the most reliable car we have owned and it still looks great after only 105,000 miles. My wife started hearing a thumping noise occasionally which we thought was coming from the trunk area. She mentioned this noise when she had the car in for other service. What they found shocked us (see video). The rear subframe had rusted through and the lower stabilizer rod had broken free on both sides of the vehicle! I see from the internet that this problem has been known to MB for years. Posts show that the subframes rust from the inside out. If you pause my video at the right points and look closely you can see there is a thick build-up of rust inside the subframe. This inside out rusting may be why our MB service personnel had not noticed this before the failure. As others here have mentioned, owners in Canada and Europe have had success in getting MB to take responsibility for this. I agree with some of the posts that it is unbelievable that this has been around this long with no recall here in the US. I have called MB Customer Care twice so far and have a case number. Both times they stated that I would hear a response within two business days but so far that has not happened. I would like to hear from anyone in the US who has had success in getting MB to take responsibility for this defect. I will provide updates as this saga proceeds.

Good luck, buddy. Hate to break it to you, but I had no success with them in NY. I hit a not so crazy pothole when I started to notice the problem. I did not think anything was severely damaged. I ended up going through insurance, which inevitably affected my premiums. I called MB HQ and all and they could care less. I'm glad Allstate took care of it, given the fact that it all started after hitting a pot hole.

Disgusting of them to not stand by this. Best of luck!

Thank you godman114 for your feedback. No big potholes or curbs for us, just puttering around our small town. I actually received a voice message from MB Customer Care this morning and am now playing phone tag. I don't have high hopes for this first encounter. However, being retired now I am always looking for interesting projects to take on

Wanted to reach out to you and let you know that the rear subframe has been added with an extended warranty from the factory. Standard warranty was 4yr / 50,000 miles and has been extended to 20 years / unlimited miles.

You can possibly be reimbursed for this repair you paid for yourself. You should receive a notification in the mail from MBUSA on this. Once you do see your local dealer on how and if they can process a credit for this now covered repair.

Mercedes-Benz USA, LLC (MBUSA) has extended the warranty for the rear subframe on the vehicles listed below, from the original New Vehicle Limited Warranty of 4 years/50,000 miles to 20 years/unlimited miles, and applies to the vehicle regardless of ownership.



This warranty extension applies to the replacement of the rear subframe under the standard warranty terms and conditions in the event the subframe experiences corrosion with perforation (holes). The extended warranty is applicable to the following vehicles:



Model Year

Model (platform)



Model Year

Model (platform)

2005 - 2011

SLK-Class (R171)



2008 - 2015

C-Class Sedan/Coupe (W/C204)

2012 - 2017

SLK-Class (R172)



2010 - 2015

GLK-Class (X204)

2012 - 2016

CLS-Class (C218)



2010 - 2016

E-Class Sedan/Wagon (W/S212)

2013 - 2016

SL-Class (R231)



2010 - 2017

E-Class Coupe/Cabrio (C/A207)

Can you post a picture of the letter? Some people never get these extended warranty notifications.

check your mail. They have extended the warranty of the subframe on my 2011 c300 to 20 years and unlimited miles.

YES, I as well received the letter in the mail for the extended 20 year warranty.

Why do some people never get these extended warranty notifications? Because the car was most likely purchased used and therefore MB has no knowledge of who is the current owner of the vehicle. Every original purchaser/owner who has not sold the vehicle and has not changed their address should receive the recall notices.

Every time I purchase a used MB, first action is to call MB of North America and register the vehicle with the VIN Number with them, so they have a record of it in their database showing me as the owner. If my address changes, the same situation. Call MB of North America and update it. Therefore, I do receive these notices accordingly.

I never got the letter, but thanks to posts on this site I finally saw the extension of the warranty announcement from 2/10/23. I called the dealer who did the work & they are now processing my refund of the money spent on the new subframe. I am the original owner, so I don't know why I never got the letter.

Anyone one from Vancouver or BC canada has this issue, looking for people to show samples of the issue to start a class action lawsuit for this issue since MB Canada doesn't seen to acknowlege this issue as a problem

Mercedes wont do sh*t meanwhile I keep getting letters for my 15 year old Honda for a rusted subframe recall and there's probably 10x less of them failing compared to mercedes.

Are you in vancouver? Cause I have a team of lawyer that will be filling it against MB canada but I need help from local people there?

Nah I'm on the other side in quebec and my subframe never failed because I rustproofed it from day one (Dealer said MB don't need rustproofing) but I have seen countless of them fail.

Do you live in Vancouver or not? I have a team of lawyer

Last summer (2024) I had the rear subframe of my 2016 E350 4Matic replaced under the extended 20 year warranty that you described above. My left rear wheel almost broke off, and the car was pulling hard to the right when braking. Notably, there was not much rust on the cracked area.

My independent auto repair shop (Specialty Imported LLC - Louis Calabrese, at West Springfield, MA, a great auto repair shop) correctly diagnosed the problem, informed me of the extended warranty at Mercedes Benz that covers the subframe replacement (price could have been ~$6K without warranty!!), and pointed me to the local dealer. Mercedes Benz of Springfield did a great job replacing the subframe and testing the car, and provided a video with the car's undercarriage maintenance inspection, for free.