Install a mechanical locking device — commonly called clubs, collars, or j-bars — that lock to the steering wheel, column, or brake to prevent the wheel from being turned more than a few degrees. Use it!
Investigate security systems if you live in a high-theft area or drive an automobile that's an attractive target for thieves. You may get a discount on your auto insurance.
Carjacking - stealing a car by force - has captured headlines in the last few years. Statistically, your chances of being a carjacking victim are very slim, and preventive actions can reduce the risk even more.