I installed a cheap Alarm I got from Amazon. Not that that will keep them from stealing it but may make them move on to an easier target. I've been thinking about how I could hook up something that will shock the crap out of them if the alarm goes off.
As I stated earlier I had major problems with theft or attempted theft in the past. I borrowed one those shocking devises for an electric fence from work and hooked up to my car. 1st night I hooked it up the motion sensor set off the buzzer I had by my bed and the next thing I hear is some guy screaming. Never had anymore problems with them fooling with the car again.