Has anyone replaced that anoying, low-volume alarm? I'd like to know if any success stories, like did it get replaced with a regular "horn" rather than a beeping device, or a professional alarm system? Thinking of replacing it myself with a regular horn, powered by the 12v accessory power in Avant trunk.

I have 2003 A4 Avant, body B6. Any suggetions? Thanks!

 

You should be able to disconnect the stock alarm horn and use the same wires to connect a 12 volt alarm siren. Any 12 volt siren should work. The brown wire is usually the ground and the other is 12V+. Check it to make sure. I did this on my 1998 A6 and mounted the siren underneath my car. It works great. and it is loud as hell.