Anyone know of any components that are direct fit for an E53? I have the factory sub and navigation. A few of my speakers are rattling when bass hits. I love the sound of the factory stereo so I don't want that to change, but I don't want to spend 70 bucks per speaker to replace them with OE's from ECS.

Anyone have any suggestions on keeping the stereo sounding factory, while upgrading the woofers in the doors and factory sub enclosure?