Audi Repair: 1997 Audi A6 audi alarm battery, a6 audi, audi a6

Question
How do I find and replace the alarm battery in my 1997 Audi A6 Quattro
wagon?

Answer
I am not sure if the alarm unit has its own battery, but the siren and module is located in the rear driver's side (US) wheel well area behine the lining.  I cannot check if these units have their own battery backup since I don't have my manuals with me and travelling out of state, but an inspection of the unit should reveal this.  Let me know,  Jan