I got a 2004 4-door Civic Si.

I recently started to notice a rattling sound coming from the just behind the driver side seat of the car eminating from what seems to be back door or near the ceiling of the car.

It only happens when I'm driving slowly or I suppose over bumpy things. I tried seeing if anything was loose or knocked on parts of the body if there was something loose inside the frame of the car but I haven't got a bloody clue what it is.

Anyone else have similar problems?

 

You should inspect all the bushings on the trailing arm of the rear drivers side suspension. Your car is getting to the age that the bushings will rot out and leave you with metal banging on metal. There's a bunch of bushings, so start at the compensator (where the toe adjustment bolt is) and work your way back.