Coincidentally, I was all ready to do the "shineydave mod", which involves relocating the horn to the engine bay, where it can just about be distinguished from the sound of a passing cricket...
Now the Audi item (8L0 951605) is £80 incl VAT, maybe a few pounds cheaper from Vagparts. For that money (or less) you can buy a complete alarm system, including tilt/motion sensors, although I guess that at that money these systems are unlikely to be Thatcham approved and therefore not acceptable to insurers.
As with all things VAG, I'm finding it difficult to get any sense out of VW or Audi as to whether the cheaper Passat siren is compatible - I know the wiring is slightly different (just to confuse us!) but that's easily sorted out - the question is will it work as I believe there must be some electronics in the box. There is also a battery backup.
Has anyone changed their alarm siren for something louder/cheaper?
Has anyone changed the complete alarm system? If so, what for and how much?
The other thought is to wire a tilt/motion sensor into the alarm circuit, irrespective of what I do with the siren.
Any thoughts, and preferably experience, would be much appreciated.
If you dont "do it now" you never will.
