Hello mate,
I have done the symphony 2 to RNS-E conversion and have a PDF guide so drop me a pm with your email addy and I will send you a copy.
Also if you do a search you should find my thread on it as it wasnt too long aago that I did it.
But basically what you need is an RNS-E from an A4 a gps aeriel a DVD
map disc and a few adapters from kufatec. Then it's a bit of wiring, coding the car and then trimming the RNS-E to fit as its not an exact fit for the 8L.