Hello and Welcome...
My name is ***** ***** Im happy to advise.
With this particular one, Im afraid it is "dealer only"... you cannot get the code from online sources.. ( as you have found)
Im mot sure what / how you mean in that you say you have had problems with dealers... but this is the only way to get the code.. the code on some of these are stored in the ecu that only Audi can retrieve or, with still others, they are on the online database ( Audi ) , that again, only they can obtain... It is a case of having to take the car to them, for either of the two types above ) - they plug into the car and it is done that way.
Whether the radio system is the original or not, that is the only way it can be done - in the case of original, they get the code as outlined above - in the case of a non original, they program the radio to the cars computer as above - that is the only way it will work - ( because it needs over writing )
I have been involved with car radio coding for many many years so you can believe what I have outlined above for you to be true.
Im sorry this may not be what you wanted to hear exactly but that is the way to get this sorted properly for you.
Let me know how you go..and / or let me know if you need anything further on this..
~>>~~>>~ Meanwhile now - Please do click on the "Exc / Ok rating" for me at this time.. "Thank you" in advance for that .
.. Note that you can get back to me anytime at all after doing the rating - it doesn't close you out --
Best Rgds, MIKE