Back seat passenger rattle

[beetle]

For those like me that have it, I found the problem. There is a u- shaped plastic guide that snaps onto a corresponding metal part that acts as a guide for the back rest portion when raising or lowering the seat and mine had fallen off. It required removing the seat for access and snapping it back on, not a hard job but cumbersome. This same piece is missing on the drivers side but it doesn't make noise.