So I'm stuck between a rock and hard place with my Audi Nav Plus. I bought my 2004 S4 last May and it had the radio upgraded to this unit. 2 weeks ago I replaced my battery and it now asks for the unlock code. The code that came with the car was for the symphony and hence doesn't work. I drove 3 hrs to the closest Audi dealer last week up in San Antonio and they got the serial # etc... after a couple of days they proceeded to tell me that they weren't able to get the 4 digit code from Audi. What are my options now?

I pulled the unit out to see is maybe they sharpied the code on it or had a sticky note. There is a piece of tape that says AA58. Anyone know what number the AA stands for so I can see if thats the code?

 

As far as I know the code is only 4 numbers, no letters.
From what I've learned from searching. The only way to get the code is from the car books or stickers which obviously won't work for you,
or pay $100 to Audi for the code. But for Audi to get it they need the matching original VIN and radio serial number.

 

Also see if you can research the previous owner through paperwork or Carfax? If you can contact them they may have it still.