It's a tough time to be a car thief. Owners are going to greater lengths to protect their cars - and its working.

The Detroit Free Press reports, "Reported vehicle theft has fallen to a 20-year low even as the number of vehicles on the road has doubled, as manufacturers install sophisticated anti-theft technology in cars and police target organized car-theft rings." According to the FBI, in 2009 car thieves stole "315 cars for every 100,000 people. That's less than half the rate in 1991," when thieves made off with "659 for every 100,000 people."

"Cutting the rate in half has a lot to do with the increasingly effective anti-theft technology that's becoming ubiquitous in cars," according to Kicking Tires. "An ignition immobilizer, which makes it difficult to start a vehicle without the owner's keys, is now built into 86% of new cars, according to the Highway Loss Data Institute. Compare that to 5% of cars in 1989. Alarms systems and GPS tracking devices have also helped curb car theft."

If you're in the market for a new car, check out the U.S. News rankings of this year's best cars as well as this month's best car deals.