1. Install an antitheft device

2. Never leave your car running or leave the keys in the ignition when it is unattended

3. Keep your car door locked at all times

4. If you have a garage, park your car inside and lock the garage door

5. Don't store packages or valuables in plain sight

6. Park your car in a safe, well-lit, or well-traveled area at night

7. Have your vehicle identification number (VIN) etched into the windows and major parts of your car to make your car harder to resell on the black market

8. When you park on the street, turn your wheels toward the curb, use the emergency brake, and try to park between other cars (this will make it harder for a thief to tow it)

9. Avoid parking your car in a long-term parking lot

10. Take out any removable electronic devices (e.g. CD player) when you leave your car

Source: Insurance.com