Rattle from the rear seat belt area.
 

Hi I am new to the forum and I am hoping that someone will be able to help me. I have a V40 D3 on a 66 reg with only 26K and there is a loud rattle coming from the rear n/s seat belt area every time you hit a bump, large or small. I have removed all of the inner boot panels to expose the seat belt mechanism and wiring loam. I have removed the spare and the seat catch just in case, but I can find no loose nuts or washers. I put down the rear seats, removed the parcel shelf and climbed into the boot. I then got my better halve to drive over as many bumps as possible. I can hear the noise which is around the area the 2 bolts holding the shocker enter the boot but can find nothing loose. Not that there is much there. There are no void spacers for a piece of weld to have broken off and rattle around in. I have attached a picture if it helps.
Can anyone suggest a reason for this or has also suffered the same thing?
Any suggestions would be helpful.