So today I successfully removed and soundproofed the drivers door. Unfortunately it started pissing down so couldn't do the passenger door. However I went for a drive and WOW. No rattles whatsoever from the drivers door now, road noise is significantly reduced and the sound system can be turned up to silly levels without any vibrations.
I followed advice on here and applied the 2mm stuff to the metal of the door in lots of small strips and then the foam stuff to the plastic inside of the door card absolutely everywhere, I used two sheets
Anyone who is wondering whether to do this or not I highly recommend giving it a go. I only broke 2 clips, very impressed