I spent a good chunk of today messing about retrofitting an OEM Bluetooth kit into my S3 Sportback (8P Facelift 58 plate) so thought I'd share the experience since judging by the number of posts on here this is a pretty popular thing to do.
I bought a new OEM kit from eBay for 250 quid which came with the bluetooth module, wiring loom, microphone and antenna.
I did my homework in advance and read everything I could find on this fine forum relating to Bluetooth. I found a lot of useful tips on here so thanks to everybody who has previously discussed the subject and answered other peoples questions since it all helped.
What I couldn't find anywhere was a proper guide or much in the way of pictures so thought I'd knock one up since it may come in handy for others attempting the fit.
The main issue that I had was with the location of the bluetooth module - the correct location (as many have previously stated) is under the passenger seat but this seems to involve taking up the carpet which I didn't want to do so I abandoned that idea.
Eventually I managed to fit it in the radio compartment behind the RNS-E which seems like a pretty sensible location to me.
I make no guarantees that any of my methods are correct but it's all gone in neatly and works perfectly. I reckon with the guide anybody should be able to do this in 1-2 hours. Considering the going rate round my way seems to be 450 quid to supply and fit I'm pretty happy with that!
There are a lot of pictures in here so I'd thought it best to PDF the thing to keep it all together:
Hope it comes in handy for someone even if just for the pictures!