Hi all, my 2018 coupe is great in everything except interior trim rattles on bad roads. It’s all quiet on good roads.

so I wonder what’s everyone’s experience and I really want to fix those rattles but it appears to me every part is rattling when on a bad road, I don’t know where to aim for fix

 

It's all part and parcel of driving a performance car. The suspension is hard, the car creaks going up and down ramps if you aren't symmetrical. the transmission is jerky, the engine throws you back. The tires are so thin they barely provide any shock absorbtion.. All this is normal. It's not designed to be soft and cushiony. As much as you fix there will always be something left over.
Sometimes things that moan and groan loudly are more exciting than the silent, reactionless types.

 

thanks for join the discussion.

I’ve owned M3 and 911 before, none of them have these interior noise even though they are firm too.. I think it’s particularly the build quality of w205 interiors..
loud plastic trim is different from loud exhaust.. but I do admit the exhaust is better than my other cars

 

This is true. Interior build quality on this W205 is not that great. Even my refreshed 2020 S coupe with revised softer riding suspension has rattle almost every section of the car.
My previous car (F80 M3) also rattled inside but was still much better compare to C63. My other car (F90 M5) is dead quiet inside.

 

My (purchased new) 2019 C63s has been at the Dealership about 3 times to fix rattles over the last 3 1/2 years. They lubed the sunroof and replaced a seal by the passenger door; another time placed felt around areas on passenger dash; and another time the rear view mirror plastic housing had a rattle and believe they put felt around the housing. Most time it fixed the rattles. Now being in the NYC area with not so great road these rattles come and then leave for awhile.
If you decide to bring it in to the Dealership I has the AMG tech take a test drive with me in the passenger seat to cut to the chase instead of me trying to explain to the SA where I think it was coming from.
I am still under warranty but your 2018 may not be so a good Indy could help.

 

this is exactly my experience, it literally rattles on every panel almost so no way to pin point to a source… though I have fixed some easy to identify.

my previous F80 only had a door seal rattle that was fixed with some tape easily… then it’s all clean despite it has stiffer suspension since it’s a comp pack

 

thanks for sharing. I’m able to find spot easy to identify and fix it myself. At 40k miles now, the entire interior rattles on bad roads, so literally no where to pin point lol. I had shop foreman sit with me and he literally said no way to fix them all