Quote Originally Posted by Purple Power View Post
ony if you do a good, stealthy install. otherwise its just as good as nothing
Well why would the install matter? If they cut wires to an alarm, they'd have to re-attach them properly, i.e. takes time they don't have. As sophisticated as even cheap alarms are now, it just would be more convenient than a bulky pig tail sticking out of the back of your jeans IMO.

As someone mentioned, a simple fuel cut-off switch could do the same too and you wouldn't have to carry anything around with you.