tmb_tango

Hi. I've had a knocking noise on the drivers rear area for a while but cant pin point where its coming from. I've put some felt tape on the parcel shelf as it sounded like it was that. This has made a slight difference but it sounds like the knocking noise comes from the drivers rear door itself. There isn't anything in the door pocket and in the floor well. Tends to happen when driving normally along normal roads, when the car flexes. Does anyone know as to what it could be or suggest anything to try? Thanks in advance.