In Reply to: no alarm on 323i posted by am I an idiot on October 22, 1999 at 11:32:26:
As we know, the E46's ignition system will kill the engine if it cannot "shake" with the chip in the key. However, there was one posting in which a car was stolen. The assumption is that the whole car was just put on a flatbed. Also, there was another posting in which all the wheels were taken.
So, for those occasions, a tilt and motion sensor may still useful, assuming the owner or someone looks out to see why an alarm is shouting. BMW's alarm would be the cheapest and easiest way to achieve this. The added advantage is that you can do it yourself and it operates with the key functions.