This has been getting on my nerves for quite some time now, and I wanted to get all of your opinions on this. My C-class's front passenger door has a hollow sound to it when it closes. It does not sound like any of my other doors. The other doors sound solid and normal, while this door sounds dinky. I notice it EVERY time the door is closed. Well a few months ago I took of the door panels off all of my doors, and noticed that the plastic protective covering was a lighter, thinner material than the rest of the doors. I also noticed that the 3 visible screws in the door (one on the plastic door peice that latches the door, the one on the bottom of the panel, and the one in the door handle) were ALL loose. They all seem to be wrong size screws, or loose. None of them will go in. They are the same size as the driver's door's screws, but screw in loosely and always come back out. That door's speaker also rattles (maybe from loose screws though) sometimes. I ran carfax a short while after noticing all of this, but everything came up clean. The door otherwise looks identical to the rest of the car, inside and out. Does this sound like a possbility that this car was in an accident before? The thing that really makes me wonder is that hollow, tin sound every time the door closes. Opinions?

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2006 E350 w/ 155k miles (Daily Driver)

Previous:
1993 300E 3.2L Sedan w/ close to about 300k miles
2003 E500 Brilliant Silver (Had 217k miles when totalled!)
1989 300E with 289,000 miles (had for <1 yr while in HI)
03 CLK 500 cabrio (Mom's)
2006 C230k (Dad's)
1999 S420 (Mom's/Dad's)
2000 C230k Sport sedans
2001 CLK320 Cabrio (Mom's)
1995 C280 My First Mercedes-Benz... (155k miles. EXCEPTIONAL AUTOMOBILE. Was Very hard to let go of!)