is the ratteling coming from loose sashbar, regulator, checker, outer handle, morror or glass bolts/rivets?
or is the door rattleing against the body.
theres a striker you should be able to adjust
its a big job if they are rivets that are covered behind the inner metal. not sure if they are like this on a mustang... there may be dimples that show where the rivets are, i hope you wont have to do this but if anyone has replaced their pw motor on crown vic/towncar