ALWAYS lock your vehicle, even if at home or in your garage.

NEVER leave your vehicle idling while you are not in the driver seat. An unattended idling vehicle is very tempting to the opportunist auto thief. Plus it is very dangerous and many states have laws against idling unattended vehicles. 

NEVER leave your keys in the ignition if you are not in the vehicle. This includes at your home, at the gas station and at the liquor store. 

NEVER keep spare keys in, on or under your car. Auto thieves know all the obvious places to look. Many key cutting services and locksmiths can make a credit card sized plastic key and holder, which fit easily into your wallet. 

NEVER lend your keys or vehicles to untrustworthy friends. You know your friends best - use your common sense. 

ALWAYS know where all your keys are.

NEVER put identifying information on your key chain. Never put your full name, address, home telephone, license plate, or V.I.N. on your key chain. If a thief finds your key chain, he will have access to and know where to steal your vehicle or burglarize your house. (Use a Post Office Box or a pager.) 

Use VALET keys when valet parking. Some vehicles have special "valet" keys which can only be used to park your vehicle. Several high performance vehicles also use special keys to limit vehicle speed and engine R.P.M. 

If you must leave your keys, ALWAYS remove all other unnecessary keys. While you are eating or watching the show, a dishonest valet parker can copy your keys and later burglarize your home or business. 

Pay attention to suspicious persons or vehicles.  Don't confront them. Call the police and let them do it for you. 

Always use your anti-theft devices.  Remember Murphy's Laws.

If you have a garage, use it.  And remember to lock your vehicle. 

At night, park in well lighted and well traveled areas.

Turn your wheels all the way to the curb. This will make it harder to tow away, and it will be more noticeable to police if they see it being towed crooked. 

When shopping, park close to the store's entrance. This place is usually safer, has more traffic, and help is closer should you need it. 

Avoid leaving valuables, packages, luggage, cell phones, pagers, garage door openers, mail or documents in view inside your vehicle. 

Never leave your vehicle's title or registration information in your vehicle. Keep the title in a safe place, such as a safe deposit box. Carry the registration in your purse or wallet. Don't make it easy for a dishonest valet parker or car washer to know your name and address. 

Never leave checks, credit cards or other identity information in your vehicle. 

Avoid moving items to or from the trunk at the location where you will park. Thieves may be watching you. 

Never leave your parking ticket stub in your vehicle. Take it with you so an auto thief cannot use it as a "ticket" out of the parking area.

If your car is broken into or stolen, call the police immediately. Stolen vehicles are often used in other crimes. The sooner you report the theft, the sooner the police might be able to find your vehicle intact, and prevent other crimes. Even if nothing appears to have been taken, still call the police and make a report. Sometimes the only items stolen are your registration card and owners manual, which auto thieves will later use to steal your vehicle or someone else's vehicle. 

Secure trailers (and cargo) with strong cables and locks, and consider using wheel bars or boots. 

As you approach your vehicle, pay attention to your surroundings. If you see suspicious persons or vehicles, do not go to your vehicle. Instead walk to a safe place and call the police. Don't confront suspicious persons or vehicles, let the police do it for you. 

Always have your keys or remote ready to unlock your vehicle. Don't spend time fumbling for your keys. The more time you take, the greater your risk of being carjacked. When shopping for a car alarm or remote unlock system, consider a system that unlocks the driver door only on the first button push, and the rest of the doors on the second push. 

Always drive with your doors locked and window up. 

Keep your vehicle well maintained and full of gas. Not only will it minimize break downs, but it will likely perform better during an emergency. 

Plan your trip ahead of time, so you know which route to take, and avoid high crime areas. 

If you have a cellular phone, make sure the batteries are charged and take it with you.

Pay attention to other vehicles which are following you. If you think you're being followed, drive into and out of high traffic parking lots (shopping centers and shopping malls), drive to a police station, or use your cellular phone to ask for help. 

Avoid driving in the far right lane.  This lane is most vulnerable to carjacking. 

Always leave room between the car in front of you. Not only can you see more, but you will also have room to drive away in an emergency. 

If approached by a stranger, drive away. Sound your horn to draw attention or help.

Do not stop for hitch-hikers or prostitutes. Carjackers could be hiding nearby.

Carjackers often lightly rear end ("tap") their targeted victims, hoping the victims will immediately get out and inspect the damage ... and walk right into the hands of the waiting carjackers.  If you've been lightly rear ended, and you do not feel safe where you are, then turn on your emergency flashers and drive carefully to a gas station or police station or where you feel safe. 

Carjackers may try to get you to stop by tricking you into believing you have a flat tire or other mechanical problem.  If you do not feel safe, then drive carefully to a gas station or other high traffic area. 

When selling a vehicle, obtain the potential buyer's name and driver license number before offering a test drive, and do not go on a test drive alone with a potential buyer. 

If you are carjacked, do not resist.  Immediately abandon your vehicle, run, and call 9-1-1. 

Alarms Systems -- Alarm systems have a variety of features: 
  Siren and/or Horn -- Activates when the alarm is triggered. However,  we've all grown accustomed to hearing "false alarms" and we now tend to ignore them. If the owner accidentally trips the alarm, he usually turns it off within 5 to 10 seconds. Unfortunately, that's all it takes for the professional auto thief to cut the alarm or horn cable, so it sounds like a false alarm anyway. Your best bet is to shop for a system with a very unique or humorous sound, atypical of what we're used to hearing. - Panic Button -- Activates the siren and/or horn from a panic button on the remote control, should you ever be surprised or attacked by your vehicle. 
- Keyless Entry -- Opens the doors and trunk from a remote control. When shopping for a keyless entry system, consider ones which open the driver door only on the first key press, and the other doors on the second key press. Should you ever be surprised by a suspect hiding behind the passenger side of your car, the passenger doors would not have been unlocked. 
- Passive Arming -- If you forget to set your alarm, the system will do it after a preset period of time (usually 1 minute). 
- Ignition Kill Switch -- Prevents hot wiring by disabling the ignition circuit unless the alarm is property disarmed. 
- Fuel Pump Kill Switch -- Prevents the fuel pump from working unless the alarm is property disarmed. 
- Flashing LED Light -- Visible notice that your vehicle has an alarm, which may ward off novice auto thieves. 
- Audible Chirps or Beeps -- Emits a quiet chirp or beep every few seconds, which may ward off novice auto thieves. But it may keep you or your neighbors awake during restless nights. 

-Data Dots - Helps police identify a stolen vehicle.  Available on some new vehicles and as an aftermarket add on.

Steering Wheel Locks -- Come in a variety of styles:
- Locking Bar -- Locks onto the steering wheel, preventing full steering motion. Brightly colored may also ward off novice auto thieves. 
- Armor Collar -- Locks around the steering column, preventing tampering of the ignition and steering locks. Brightly colored may also ward off novice auto thieves. 
- Steering Wheel Guard -- Completely covers the steering wheel, preventing cutting or removal of the steering wheel. Brightly colored may also ward off novice auto thieves. 
- Brake and Clutch Locks -- Locking bars which attach to the brake and/or clutch pedals and the steering wheel, preventing the vehicle from being driven. 

Tracking Devices -- Allows the police to quickly locate stolen vehicles, and increases the chances of apprehending the suspect.  Such as:
Boomerang Tracking
intertrack
LoJack
Networkcar
OnStar
Satellite Security System
TeleAid (through Mercedes Benz)
Teletrac
VehicleTrak

Ignition Kill Switch -- Hidden switch to turn on and off the ignition circuit. The switch can be hidden almost anywhere, from under the dash, on the drive door panel, in the headliner, or under the hood. 

Fuel Pump Kill Switch -- The same idea as an Ignition Kill Switch. 

Hood Locks -- Key locked hood pins or latches which supplement the stock hood latch. 

Wheel Boots -- Locking bar or boot which attaches to a wheel, preventing the vehicle from being driven or removing the wheel. Used mostly on trailers, but can be used on cars and trucks. 

V.I.N. Etchings -- The vehicle's V.I.N. is etched on all glass surfaces, deterring theft of the vehicle for those parts, and making identification easy. The V.I.N. can also be engraved onto wheels and other components.