I grew up next door to Texas and have been using a firearm of some sort since I was in the third grade. CA or not, wanna come messing around with my personal property against my wishes, you do so at the extreme risk of perforation of some sort, but thanks for the stereotype.
Also thanks for missing my oh so obvious point which was not about his protecting his personal property, but his highly misinformed methodology. A 12v car battery simply won't shock you and you can prove it by touching both terminals at the same time. Only the ignorant think that can work. If you would like to get a capacitor or coil and hook it up to the battery to drive the voltage up high enough to do some good, that will work, but otherwise, not so much.
All you need to do is make sure some lady out for a stroll with her munchkins doesn't lose control of them long enough to let them enjoy your vandal deterrent. That would be a really crappy way to lose your rig.