Every time I leave for a business trip, my 17 year old son steals and drives around in my car with his friends. I've tried hiding the keys and locking the garage, but he still gets in there!

This month I'm going to Boston for a week and I plan on booby trapping the car to scare my son from stealing my car ever again. I've already cut the brake lines and loosened the nuts on the front tires.

Does anyone else have recommendations to booby trap my car? Thank you in advance.