The ignition disconnect in my wife's old Saturn was a small push-on, push-off switch installed in the bottom of the ashtray. She kept assorted hard candies in the never-used ashtray, and they hid the switch very well.
One common misconception among many people - including some gun owners - is that it's OK to shoot someone to stop a property crime like car theft. In my state at least, it is not. You will rightly go to jail. When I took my concealed carry course, everyone else in my class was a biker...er...Harley Davidson owner, including the instructor. At one point in the class the instructor was quizzing us on various scenarios, and he asked the group if it was legal for them to draw their gun on someone stealing their Harley. Nearly everyone raised their hand. And they were all wrong. ;-)