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.

I have a broken clip on my door panel so sometimes it will rattle. If I lean against it the rattling stops. I've got to rig up something to make it tight. Good idea though.