1) Turn on radio and the radio display shows "SAFE", thus the problem.

2) Press the P.Scan and RBDS buttons simultaneously (at the same time) and hold until "1000" is displayed. Release the buttons but Do NOT press buttons again as the radio will think the "1000" is the code.

3) Use Preset buttons 1 through 4 to enter the four-digit code number from your radio card that you got when you bought the car. Preset button 1 corresponds to the first digit, preset button 2 corresponds to the second digit, and so on and so on.

4) Once the code shown on the display is correct you must press the P.Scan and RBDS buttons simultaneously and hold until the word "SAFE" appears in the display again. Once the word "SAFE" appears you can release the buttons.

4) The radio should unlock and be available shortly afterwards.

5) If an incorrect code is entered, the word "SAFE" appears, first flashing and then continuously. You can repeat the above steps to unlock the radio once more, the number of attempts will be shown in the display. If an incorrect code is entered again, you radio will be locked for about one hour. After one hour - the radio must stay on and the key must remain in the ignition lock - if the display goes out, the you can repeat the above procedure to unlock again. The cycle - two attempts, one hour lock-up - still applies.

6) If you lose your radio code, contact your Audi dealer as you are SOL.

http://www.ibiblio.org/tkan/audi/radios/symphony.html