Since I bought the car a few weeks ago, there has been an annoying jingling noise behind me, driving me mad.

However, at the weekend, 4 up, I noticed it stopped.

Checked the rear seat mounts this eve, and the 2 17mm bolts were loose and the washers were rattling!
Tightened them up and in a brief drive it seems all good!

This has been sending me crazy for ages. I just looked and mine has the same problem. This post has saved my sanity!