I think nobody here has looked into this so far and could help. But you can do your part to get an answer and the BT adapter working.
The BT phonekits do not get connected to the RNS-E, they get connected to the car and the CAN-BUS (besides microphone, speaker, HU, etc.). The RNS-E then talks via CAN-BUS to the BT phone kit and allows some iteraction, like acepting the call.
Some questions which might help to get you started:
What car are you driving?
Did you confirm that the 8P0 unit was actually used in your car (8P0 indicates an A3 unit but the A3/A4 share several components).
Did you confirm that this unit is actually a BT phone kit (might not have BT if it's to old)?
Did you check where the unit is originally installed when it comes as factory option?
Can you post pictures of the unit and the connectors?
Is there any wiring diagram on the unit?
Did you try to get a wiring plan to see how it should be connected?
Once you have answered the questions above it should be possible to design a cable (if there is no OEM harness for this purpose) and ask Kufatec to make this cable. Or did you already try to contact them and they said they can't do it?
If i am asking to the forum it is because i asked everywhere and nobody answered me, i asked also to Ralf Deventer and Kufatec but deventer can't help me and kufatec didn't answer, the adapter is for my car because on the vag com results that it is a bluetooth adapter for Audi A3 8P.
1)So my car is an Audi A3 8P,
i have an Rns-e with tv tuner + Bose system installed by the factory.
2) i don't know how to post photos so if you tell me how to do?
3) the cable i think because i saw a cable about the tv tuner is similar because the interface has 54 pin ( 18x3 ) and one for the antenna.
My car is 2004 made and the new model of audi a3 can support the bluetooth phone.