Recently purchased 2005 A8L; a few questions mainly regarding MMI updates
 

Last week my Dad bought a 2005 A8L (3.0L CVT), replacing his recently scrapped 1999 A8. We picked the car up in England and drove it home ~300 miles to Scotland, using the woefully out-of-date sat nav. I've been looking into updating the navigation data and saw that it may also be possible to also update the software for the MMI (it looks like the MMI has never been updated - currently version 1110 IIRC).

The procedure looks pretty straightforward, and there are quite a few sources for the update CDs available online, however, one of these sources: AUDI A6,A8,Q7 MMI UPDATE SET 4CDs "SW 5570" , MMI HIGH 2G, set 2015!! | eBay states quite clearly that the disks they supply won't work for a 2003-2005 A8. Could anyone here shed some light on why this might be?

I'd also like to replace the now useless analogue TV tuner with a digital tuner and do an AMI retrofit for the car, and I understand that a software update would be required first.

FYI: I have deduced that the car has a MMI 2G High (the screen is definitely a colour screen). There is a small phone handset tucked away in the driver's-side armrest with a sim card slot underneath it (still reading the manual to find out how that's supposed to be used).

If anyone has any insight or advice about anything I've mentioned or just has some useful information about the car please let me know.

Thank you all in advance. :)