Window Rattle Actualy Exterior Trim!
I think this will only apply to later cars.
Just incase anyone else has searched in vain for a rattle in their doors.
I took the interior trim off my front door to hunt down a rattle, I decided it came from the window mechanism so I left it.
I just noticed the other day when I shut the passenger side door the outside plastic "slab" was visibly rattling.
I've wedged a bit of cardboard inbetween the metal & the plastic and the rattle has gone (after a quick test drive).
Thought that might help someone.