🚀 go-pugleaf

....
	The Robert Bosch Co. sells a modular alarm system. You buy a basic
	system and you can add the motion sensor module, the ultrasonic
	module (+others???). They are as usual expensive, but seem to
	be of rugged & sound design. (For example, if you jump or cut the wires
	to the key switch, the alarm will go off, whether the alarm is
	armed or not. Same thing with the radio. The alarm will go off
	when someone tries to steal the radio, whether the alarm is armed 
	or not. I am not sure if this is a common feature with other 
	alarms.)

	Instead of opting for a motion sensor, consider an 
	ultrasonic detector in the car's passenger compartment.
	When the car is rocked it will probably not go off unless your
	seatbelts wiggle sufficiently, or something falls over; but it
	will raise hell if someone tries to enter the car in an unorthodox
	manner (without opening the doors). 
	(Problem=>
	what if a moth is in the car...)

	In general I don't think there is a fool proof alarm system.
	If a "profesional" thief wants to get your car, he will.
	You just want to scare off the small time thieves.

	Another piece of advice: do connect the alarm to your lights
	or hazard lights. Ever heard an alarm go off on a large parking
	lot without the lights flashing? It is very hard to identify where the
	noise is coming from.

Good luck, Jan.