My rattle/buzzing problem solved
I could have sworn that a buzzing / rattle noise was coming from my driver's side A-pillar on my '95 E420. But one day when it was making the noise and sunny outside, I moved my driver's side visor and the buzzing stopped.
Sounds travel very strangely inside a car. I would never have guessed that the sun visor was the source of so much frustration.
So - don't be so sure about the location of your car's funny noises. The real culprit could surrprise you.