What are the three most important things when buying a home or setting up a business? Location, location, location. Turns out those are the three most important things to car thieves too.

The National Insurance Crime Bureau (NICB), which has been tracking stolen vehicle rates by state since 1985, released its annual report identifying the most stolen cars in 2007 earlier this week. Ahead of that report's release, in the spring the group announced which American cities have the highest rates of car theft. Like everyone else, car thieves just love sunny California.

The NICB tracks metropolitan statistical areas for vehicle theft rates, determining them by the number of vehicle theft offenses per 100,000 habitants using the 2007 U.S. Census population estimates. Four of the top 10 cities for auto theft in 2007 are in California--and all four are in the top five, in fact.

Modesto, Calif., ranks at No. 1, with San Diego/Carlsbad/San Marcos in the third spot, Stockton in fourth and San Francisco/Oakland/Fremont in fifth place. The city in second place, the only one in the top five not in California, is Las Vegas/Paradise.

"One huge factor is that there are more vehicles in California than any other state, making it a target-rich environment to begin with," says Frank Scafidi, NICB spokesman. "The proximity to international borders and seaports is also a factor. Both are widely used in the illegal exportation of stolen vehicles."

But the main attractions are the car theft hot spots conveniently located near the Mexican border. A quick trip across and crooks can quickly unload stolen cars--or their parts--without hassle or question. That's why Texas, New Mexico and Arizona are "all high-theft states" as well, Scafidi notes.

"There is a secondary market that is operating outside of the mainstream that buys and sells parts from stolen vehicles," says Rod Davis, vice president of programs and services for the Council of the Better Business Bureau. "We don't know how big this market is, but they are doing a lot of business in the border area. Chop shops in Mexico are more prevalent."

That's not to say car thieves don't do the same sort of thing without crossing the border, but they have to know which auto service centers and garages will take stolen parts and vehicles without proof of ownership. If you take your car to a service center, keep in mind that all replacement parts should come with a warranty, and if they don't, there is a chance you're getting a stolen part, says Davis. Also, ask your service technician where the part was purchased.

"Legitimate garages have systems in place for getting parts from proper streams of commerce," says Davis. "If it is not legitimate business and you are doing business there, then you are more likely to encourage stolen vehicle activity."

There is a bright side to all this, however. Despite the prevalence of car theft in certain areas, there are early indications that motor vehicle thefts overall were down nearly 9% in 2007, compared with 2006, the NICB says. The final data will be released later this year.