It's taken me a while to work this out, but the annoying rattles that I hear right behind me every time I'm driving on a rough surface road, I now think is coming from "inside" the passenger seat back, and not from behind the trim panels separating cabin from engine compartment, as I first thought.

Last weekend I went for a drive with the passenger seat tilted forward as far as it would go (until the top hit the sun visor), and I am sure the noise "follows the seat back".

Anyone else had this problem? How do you get inside the seat back? I think it may be something to do with the internal lever mechanism and linkages at the top of the seat back that allows you to tilt the seat back forward. But the driver's seat seems OK.