[Rymanrph]

To me it sounds like an interior panel piece going nuts. I had one clip in one of the side up near the back seats that some how got bent like crazy and I couldn't bend it back to put in, so I thought it was probably that knocking around, but its just the same after I took it out. It could be that panel knocking without that clip, but I seriously doubt it because the rattling is coming from much further back in the car only on the passenger side (clip was on the same side though). I though about doing dynamat, but right now, its just not worth the money.