OK, good people of Copenworld, I have at last saved up enough of those shiny gold discs to purchase a new pair of Fli speakers and an In Phase ultra compact active subwoofer for Neville. I replaced the speakers last weekend, which entailed drilling new holes in the door and a little bit of soldering. All good except when I set the bass to what I would term a decent level, the door cards/door rattle like my Granny's teeth in a glass of water! So ... I have purchased some Silent Coat sound deadening material and my question is where best to place it: the YouTube videos all show it being placed on the inside metal part of the door (having removed the plastic weatherproofing) but should I place any on the inside of the door cards as that seems to be where the bulk of the rattling is coming from? Any advice on this would be much appreciated. Do I tuck any in behind the speakers themselves? The subwoofer will eventually be mounted between the seats - do I need to do any soundproofing work in this area????? I'm sure that once this is all completed properly the improvement is gonna be massive! Many thanks in advance, Copenistas, for any nuggets of advice or experience that you can offer.