Does anyone have rattling noise coming from the bass sepaker (HK L7 system) when playing really low bass? It does not happen all the time but it is annoying. I had similar problem with my 2009 C class which the rattle happened all the time and it turned out that the mounting bracket wasn't fitted properly. Usually the dealers are really bad in fixing this kind of stuff unless you tell them exactly what is wrong (it took me 4 trips to get that fix on my C class last time). If anyone has the same problem and know what's the fix for it, please share with me. Thanks!

I have the exact same problem on my coupe. I took it to the dealer 2x for the same thing. The first time, they said that they didn't hear it, so I ended up having to demonstrate it in the service drive for them before they would look at it. The second time around, they told me they compared it to another 550C on the showroom floor and that it made the same rattle noise when listening to the same track. They said that it was a "product characteristic" and that there was no fix or problem at the time. I've been dealing with it off and on for since then. It only happens if the track has really low bass but it can get very annoying. I have found that raising the rear sunshade makes it go away. So, for now, I raise the screen when it bothers me and put it back down when the song is over.

Thanks for the quick reply AJRDU!
I tried raising the sunshade as you said and the rattle did go away. I am sure we have the exact same problem so it does seem like it's a common problem for all E coupe.
I don't think calling it a "product characteristic" is an acceptable excuse for the dealer not to do anything about it. I would call it a "design flaw", if it affects all product, Mercedes should address it.
I also found one thing, I can also stop the rattle if I press on the sheet metal inside the trunk (underside of the rear parcel shelf) around where the bass speaker is mounted. I will continue to find a fix for it but for now I will keep my sunshade up, Thanks for the tip! If you find a solution for it, please let me know and I'll do the same

the rattle is due to the rear shade,
i believe its the plastic of the shade rattling

hi guys, a friend of mine here in the uk had the same problem with his e coupe. the dealers kept saying the same thing. no fault found. one dealer even stated that it was the music he was listening to that was causing it. anyway to cut a long story short he escalated the problem via email to head office.

see emails below

Furthermore none of the faults on my car were repaired, and to add insult my £700 extra Harmon Kardon sub woofer rattling was claimed to be a fault due to the music that I listen too. That is absolutely ridiculous. Whilst listening to the radio my back shelf rattles profusely. Basically the design of the shelf is completely wrong as low bass tones rattles the shelf. This is a common fault with all new E-class coupes fitted with the Harmon Kardon upgrade. Therefore I found it completely insulting to suggest that this rattling was due to the type of music I listen too. Does a £700 extra only work with a specific genre of music?

this is the email response from Mercedes customer service

With regards to the issues with the Harmon Kardon Audio System, our Official Workshop has now agreed to consult with Mercedes-Benz Technical for advice on how to fix the 'rattling' whilst your vehicle is on site.

Lynne.Smith@mercedes.co.uk
Nitin.Varsani@mercedes.co.uk
Billy.Swaby@mercedes.co.uk

all three of these people were cc in on the emails but it was Lynne smith who escalated the problem.

mercedes finally took his car in and sound proofed the whole rear parcel shelf
which is were the problem is. all fixed now

hope this helps guys

Hi everyone,

i have the same problem on my 2010 e350coupe

i took it to the dealer 3 times and no one can figure out whats wrong, they just show me the same CD in another 350 coupe and show me it makes the same sound.

Have HK system. Have the rattle when playing bass.

I solved it for under $10.

I bought some little rubber window vibration stoppers from a hardware store (they are like mini rubber door stoppers).

Step 1

I then went in the boot/trunk and put the rubber stoppers in various places where the subwoofer chassis is near the frame. I wedged the rubber in between. This reduced 50% of the rattle.

Step 2

I went inside the car.

I wedged 4 rubber stoppers, equally spread, between the edge of the rear deck and the bottom of the rear window.

Result: 99% reduction in rattling when bass is present. I no longer have to drive with the fade +6 and the bass - 3.

Now the fade is equal and the bass +4.

I hope this helps.

all coupe's rattle more or less with a full bass
i installed some foams all around rear deck myself and the issue is gone