I had an annoying rattle which I assumed was coming from either the interior of the DS door; or someplace within the body cavity rearward of the door jam. It sounded very much like metal on metal, not heavy pieces, but more than a wire or bracket vibrating. Looking for this gremlin I spent at least five hours pulling door panels, trunk interior panels, rear seats and speaker enclosures, etc. Gas filler lid.

Yep it was the round exterior body panel lid. One day, while waxing the car with an orbital random, as it passed over the lid I notice it created the same rattle. So I stuffed a folded rag on the gas cap, shut the lid, drove it over the same roads causing the rattle... viola. No rattle. A permanent fix was simply sandwiching a one inch square strip of self adhesive rubberized weather stripping under the cap to prevent vibrating against the body panel.

I'm not sure if I should feel brilliant for finally discovering the source of the rattle, or feel dumb because it was in such an obvious location in the first place. Either way, if anyone is looking for that same elusive rattle... try this fix.