Remove visible items: If you leave items visible in your car, you are a target. Be aware that someone may be watching as you put a wallet, purse or cell phone under your seat, especially at a gym. Take these items with you. Don't leave anything in your car unless you would be willing to throw it away.
Lock it up: Lock your vehicle and take your keys, even for quick errands. Lock the trunk, hatchback or tailgate to block access into the car. Close all windows, including vent or wing windows and sunroofs. Buy a steering wheel lock or alarm and use it. Many people believe that alarms no longer make a difference; however, they do remain an effective deterrent to a burglar. Criminals will choose the easiest target. If they have two cars to choose from one with an alarm, one without they will burglarize the one without.
Park smart, safely: At home, park your car in the garage if you have one. Lock your car and all garage doors. Don't leave the garage door open just because you are home. Away from home, always park in a well-lighted area and check to see that your vehicle is visible to pedestrian and vehicular traffic. The more exposure, the less attractive your car is to would be thieves which also means, don't park in alleys or other areas with little foot or car traffic.
Keep in mind what catches a vehicle burglar's eye: Briefcases, day planners, mail, cash or coins in cup holder or ash tray areas, computers, cell phones, CDs, stereos, garage door openers, gym bags, tools, purses, keys and jewelry.