I know this sounds crazy, but a friend of mine told me about the years ago. I did it in my Tundra and it worked.
Dum Dum - Plumbers putty. You can ball it up and place it on the interior of the door panel where it will press against the door shell.
It does 2 things. One it causes the trim panel to fit tighter against the shell and it adds density to the trim panel which absorbs vibration.
It is fairly stable so it won't melt and drip into anything. Had it in the Tundra door panels for 8 or 9 years, never caused a problem.