If you're living in California, don't keep your car unlocked. Four of the top five cities for car thefts are in the Golden State, according to a new report.

The National Insurance Crime Bureau reported Tuesday that the Modesto, Calif., metropolitan area had the highest per capita rate for vehicle thefts in the nation in 2007.

Las Vegas came in No. 2, followed by three other California metropolitan areas -- San Diego, Stockton and San Francisco.

The rate was determined by the number of vehicle theft offenses per 100,000 residents using 2007 U.S. Census population estimates.

But there is good news on the car-theft front: 2007 is on track to be the fourth consecutive year of declining vehicle thefts. And if the preliminary figure of -7.4 percent holds, it will be the largest drop in thefts in a single year since 1999.

Officials caution, however, that the good news is no reason for vehicle owners or law enforcement officers to relax their vigilance.

"Bait cars, license plate readers and owner-applied theft deterrence and recovery systems have delivered outstanding results," said Robert Bryant, NICB president and CEO, in a news release. "In the coming years, technological advances may well defeat vehicle theft as a major crime problem in the United States, but until then, we must continue using everything at our disposal to keep achieving the kinds of results that we have had over the last four years."

In their annual report, NICB analysts reviewed vehicle theft data obtained from the National Crime Information Center for each of the nation's metropolitan statistical area, or MSA.

MSAs are designated by the Office of Management and Budget and often include areas much larger than the cities for which they are named. For example, the Modesto MSA includes the entire county of Stanislaus and other municipalities in addition to the city of Modesto.

For 2007, the 10 MSAs with the highest vehicle theft rates are:

1. Modesto, Calif.
2. Las Vegas/Paradise, Nev.
3. San Diego/Carlsbad/San Marcos, Calif.
4. Stockton, Calif.
5. San Francisco/Oakland/Fremont, Calif.
6. Laredo, Texas
7. Albuquerque, N.M.
8. Phoenix/Mesa/Scottsdale, Ariz.
9. Yakima, Wash.
10. Tucson, Ariz.

• Map: Rankings By State

Prevent Theft

The NICB recommends the following actions to vehicle theft protection.

Common sense: An unlocked vehicle with a key in the ignition is an open invitation to any thief, regardless of which anti-theft device you use. Secure your vehicle even if parking for brief periods. You should always:

• Remove your keys from the ignition.
• Lock your doors and close your windows.
• Park in a well-lit area.

Warning device: The second layer of protection is a visible or audible device that alerts thieves that your vehicle is protected. Popular second layer devices include:

• Audible alarms
• Steering column collars
• Steering wheel/brake pedal lock
• Brake locks
• Wheel locks
• Tire locks/tire deflators
• Theft deterrent decals
• Identification markers in or on vehicle
• VIN etching
• Micro dot marking

Immobilizing device: The third layer of protection is a device that prevents thieves from bypassing your ignition and hot-wiring the vehicle. Some electronic devices have computer chips in ignition keys. Other devices inhibit the flow of electricity or fuel to the engine until a hidden switch or button is activated. Popular third layer devices include:

• Smart keys
• Fuse cut-offs
• Kill switches
• Starter, ignition and fuel pump disablers
• Wireless ignition authentication

Tracking Device: The final layer of protection is a tracking device that emits a signal to police or a monitoring station when the vehicle is stolen. Tracking devices are very effective in helping authorities recover stolen vehicles. Some systems employ "telematics," which combine GPS and wireless technologies to allow remote monitoring of a vehicle. If the vehicle is moved, the system will alert the owner, and the vehicle can be tracked via computer.