Audi RNS-E: Digital Tuner Upgrade

Hello everyone,
'I'm sorry for speaking English.'

My goal is to connect Bluetooth (A2DP) as an auxiliary input, or ideally, to replace the digital radio. I purchased and tested a Sirius receiver, but there's a problem: in the EU version, I can't code it, and the Sirius receiver doesn't communicate with the radio (it sends a few frames and then goes to sleep after a couple of seconds).

I saw that there's a possibility to code a 'digital tuner', but I have no idea what components I should connect.

'So, maybe someone here knows the part number. Also, if it works similarly (from a user interface perspective) to Sirius or XM, or if there's a way to use a Sirius or XM receiver without losing the odd frequency.'

Sure, here's the translation:

'Thanks in advance.'
by the way
I have some information about the CAN bus system for the PQ35 (VW416/428) engine. I can't share it directly, but if someone asks about a specific CAN ID, I can check it.

Sincerely,
Lukasz.