Symphony/CD changer/Fascia help needed

OK guys I need some help.

I picked up a symphony head unit, CD multichanger and lead at christmas from various sources (on here and on ebay) but have only just got around to fitting it all. I had the car apart on Satuday to run the lead from the dash to the boot behind trim and under carpets etc. and plugged it all in to find the following problems:

1) Illumination - The new symphony headunit (from an Octy by the look of things) does not light up with the side/head lights but everything else appears to work fine. From a few searches on here I think it needs a tweak with a Vag Com to change a "My Diagnostics" code from 0403 to 0407. Is this correct? Also is there anyone in the Sheffield area with a Vag Com who would be able to do this for me?

2) Sound Quality - The multichanger all fires into life and appears to work OK (plays disks and can scan between disks and tracks) but the sound quality is absolutely crap - a wet fart noise almost like the speakers have gone but I know they haven't as they are fine with the radio and tape. All parts were sold as being in full working order but it almost sounds like the signal is being clipped or there are some real bad connections somewhere. I've checked what I can but any suggestions? Could it again be a Vag Com setting somewhere?

3) Fascia - I have the OEM dash fascia filler for above the Din sized symphony unit but am not completely happy with the fit. The new headunit is flat fronted and the dash is convex from top to bottom and from side to side. This means that at the bottom of the headunit the lip of the cubby hole sticks out a few millimeters beyond the headunit, leaving a gap on top and making it all somewhat unsightly. Have others had this and how did they solve it? Would an aftermarket fascia adapter that goes all round the headunit help (for example an Autoleads one?) or does anyone know of a make that takes up this convex shape?

Cheers