I have struggled on getting the unlock code for my radio and had an appointment set at a dealership. to get this done.

Then, over the weekend my girlfriend found a different way. So, if you're looking to not spend any money, here it is:

call: 1-800-822-2834
....this is Audi directly, not a dealership

wait on the line till you get a representitive. tell them that you need the unlock code for your radio. Then, give them your vehicle identification number (vin) and the serial number off the side of the radio. (an AUZ number) Then they will give that info to their techs, and either call you back the same day, or just give them a call the next day. They didn't call me, so I got mine the next day.

Enter your four digit code and walla, there shall be music!!!! I was so happy to not have to spend 60$, plus the amount on gas, since I live in a small town and the nearest dealership is 50+ miles away.

 

This didn't work for me since my radio was originally from another car. I did find a 100% foolproof method though, if you're handy with a soldering iron and not afraid to take the radio apart you can read the code directly off the EEPROM chip.