If I bought a (lets say) 2011 TDI JSW with the (non) GPS unit. If I were to swap in a 2012 or up RNS510 with voice command... I would have to remove compass module, add Bluetooth module, and ad microphone if the 2011 JSW was not Bluetooth optioned (were some non BT anyway?) and then code it?
Anything else?
I'm not an expert at all, but I remember a lot of noise about the bluetooth integration with certain years and options on the cars. My car was simple to fix, the 9W2 bluetooth box was under the passenger seat and all I had to do was plug in a better 9W7 box that was readily available at the time for about $200 as I recall. And after a time, after many complaints and I guess a court ruling, VW offered a less than stellar upgrade (from what I heard), or they gave us cash if we already did the upgrade ourselves. I got a check that paid for my 9W7 upgrade!
Then there was also a time when bluetooth came in the radio, not under the seat. Then guys were having to add the harness to add the bluetooth if they upgraded the radio. I checked the link below quickly, and it looks like maybe bluetooth in the radio was only with the 315 nav unit. Maybe it was still under the seat in other cars. The facts at the link indicate that the 9W7 came standard on the car in 2013. Correction, 2011!.
bluetooth-faq-for-vw-golf-jetta-jsw-9w2-9w3-9w7-modules
Below is a link with facts about the different years. They mention bluetooth modules, but it might take some digging using the links at the link to find all the information you need.
2010-2011-VW-Golf-TDI-buyers-checklist
Here is a great link!
Scroll down to the section, "Bluetooth, GPS navigation, and interior electrics"
2010-vw-golf-tdi-sportwagen-wagon-2011-vw-jetta-tdi-faq-how-to-index