I've tried everything so if anyone has any ideas let me know. When I drive over bumps or uneveny roads I hear an annoying rattling sound coming from the driver's side rear area, possibly from the door. I have tried EVERYTHING: removing the door plate and seeing if anything it loose, taking out the rear deck, driving with the door open, seeing if the bose speaker is lose, driving with the seats down and the seatbelts plugged in, checking the trunk for anything loose.

I seriously am desparate. This seems like an EASY problem to solve. I bought this car used a week ago and I assumed I could fix this quick. Now I don't know. It's the most annoying thing.

 

Are you positive it's not a suspension noise? Maybe a bad ball joint or strut mount, or a broken spring? A4s are known for ball joint failures, strut mounts aren't unheard of, and I'm not the only one who has recently discovered a broken rear coil spring (thankfully mine broke on a part that is flat on the perch, so it's no big deal). Might want to look in the wheel well for anything broken, loose, or suspicious.

 

I've thought it might be a suspension issue but the thing is that when I drive it on smooth roads like on the freeway I don't hear a thing. It's only when I'm on local streets and I drive over bumps, etc. that I hear the rattle. If it were a suspension issue wouldn't I be hearing something all the time?

 

Not really - if the road is smooth, the suspension isn't moving around. When you're hitting bumps and dips, your suspension is compressing and the control arms are moving around, and that's when you'll hear the noise.