My A4 is a 99.5 saloon (sedan) with manual windows in the back. The stereo is the standard Concert system with six speakers. I don't like the location of the rear speakers in the parcel shelf, and am thinking of fitting new ones. What I had in mind was to mount new mid-range drivers in the lower part of the rear door panel, and small tweeters higher up. Has anyone tried this, and if so, how feasible is it? What size speakers will fit into the door panel? Can they be wired into the existing rear speaker loom, whilst retaining the shelf speakers, or would I have to disconnect the shelf speakers altogether & divert the cabling to the new ones?