Retrofit RNS-E

Hello

Thinking of swapping my the symphony unit in my 2006 B7 A4 cabrio for an RNS-E.

Does anyone have personal experience of doing this swap? How difficult is it to do? 
I believe I’d need a GPS antenna and possibly a Bluetooth module also?

To what extent is it plug and play? I assume I’d need a loom adapter? I don’t know anybody who would have the ability to mess around with the ECU coding. So I’d need to seek help from a garage to do that. 
 

im being encourage to just get a cheap car play interface from eBay, but I prefer the idea and look of having the OEM unit.

im in south wales if anyone knows of any garages or installers who could help me.

thanks for any advice offered!