Can someone please tell me where the alarm siren is located on a 99 A3 tdi please i just cant find it??

 

I believe it is located in the boot, behind the cover on the passenger side. The central locking unit is also in that location (and is probably part of your alarm), typically wrapped in foam at the base of the 'bass' speaker.

 

Why does the alarm sound like a truck backing up?

 

The alarm on my 2003 1.8T sounds like the bleeps of a microwave, which I suppose could sound like a truck backing up! It is probably the worst alarm sound I've heard! Its hardly a Clifford!