Well, I have decided to go for the Symphony II+ over the RNS-E for my 2002 A4.
This is due to the fact I don't really use satnav - and when I do I use my phone.
The main reason I was going to go for the RNS-E is due to the fact it plays MP3 & music can be loaded to SD cards.
However, due to cost restraints I decided to go for the Symphony II+ as it would allow me to load 6 MP3 CDs with a slight increase in sound quality.
It took me two weeks to track one down, must have sent in excess of 50 emails and around 20 calls to breakers.
Finally found one yesterday from a 2008 A4 on ebay USA which I snapped up - shipping was $47 and I got the unit for $150 which I was pretty happy with.
However, I have a few questions;
Obviously being a full canbus unit, the Symphony II+ requires a quadlock connector, will the one for the RNS-E work?
I have found the following, so taking it that it probably will work?:
KUFATEC GmbH & Co. KG - Audi Bundle Adapter Radio- Navigationseinheit BNS 5.0, Concert 3 35713
2nd question is coding. With the unit being from America, I am taking it the coding will be slightly different.
I have found the following, but I am unsure as to how it is done (I have access to a genuine vag-com cable & software)
Audi Radio Generation II Plus - Ross-Tech Wiki