I know I’m grave digging, but a solution for anyone else having this issue:
buy some sort of foam tape, just needs to be a few mm thick. Take the door trim off and look for a few spots around the speaker where the rattle might be caused, it will probably be where the speaker grille/surround comes within a few mm of the speaker/door. Put some of the foam tape on these spots. Avoid any of the speaker. Put the panel back and blast your sound, if it’s not fixed try again with another layer of foam tape as it may not be bridging the gap.
this should apply to any sound deadening you want to do.