I had an awful knocking noise from the near side. It normally appeared at low speeds, on uneven roads or when cornering. I was pretty much convinced that I needed to replace the rear suspension bushes but couldn't detect any play despite pushing and pulling everywhere. This went on for a month or more before I managed to create the noise with a violent sideways shove on the roll bar. After a few more shakes I finally tracked the noise down. When I ordered the kit 20 years ago, I didn't specify 4 point harnesses, so it came with 3 point lap and diagonals. When I later installed harnesses I left the 3 pointers in place and the noise was the tongue of the belt swinging and knocking against the side skin behind the passenger seat. I still have no idea why it started clonking after 19 years but I was very relieved to find the source.