Brief description, anti-theft alarm: Siren
WARNING: This page is about a different car, the 2001 Saab 9-3. However, it is still accessible from the selected car via links, so may be relevant.
The siren unit is located at the rear edge of the left-hand front wheel housing. It has two piezo-electric sirens and is equipped with back-up batteries so that it will sound even if the ordinary car battery is disconnected or dead, or if somebody cuts the leads to the siren unit.