I mentioned on another thread that I replaced those little windows (on my 740 )with plexiglass to they could be popped out (in actually) by someone attempting to break them. On my current Volvo (940) the chime is in the relay compartment and easy to find by the sound. I wonder if a loud bullhorn hooked in with a timed relay would drive out the intruder- or a piercing interior siren. Also a few red LEDs always on might make the car appear to be highly secure - even though it isn't. The LEDs might do the trick since a thief might be planning on breaking into 3 or 4 cars on the block and the light warns him that he'll need to flee if he starts with yours.