For as long as I have owned the car I would get a rattling/buzzing sound somewhere behind the front seating area. It sounded like a loose wire or some other object vibrating. I took it on bumpy roads with the Tesla SC but we could not duplicate it. It mostly happened on a road near me that had a lot of patches. Rather than bumps, the road was more like a constant oscillation. Tesla SC could not find anything loose so they were going to order me new door panels. A month or so ago Tesla Mobile came out to replace a 12V battery so they asked if the mobile tech could go with me on my "vibration" road. We took it out and he sat in the back and definitely heard the noise. Coming back we noticed that the plastic cover on the leading edge of the drivers side FWD would rattle if you tapped it. He said all the cars are that way and when the door is closed it should snug up to the body and not rattle. Well my car did not behave this way. So the tech took off the covers and put in some padded foam strips to buffer any rattling that might take place. I have driven the car now for about 1k miles and the vibration is either gone or not even noticeable at this point. I think another solution would be replacing the Tesla hard plastic attachment buttons (the ones that look like a Christmas tree) with ones made of nylon. They would be able to pull the trim piece up tighter IMHO. Anyway if any of you are plagued with the same situation, you might try this solution too or suggest it on your next SC visit.