AIKEN --- Better lock those car doors.

A recent study has found that automobile thefts in the Augusta-Aiken metropolitan area were up last year and that nearly 300 more cars were stolen in 2007 than two years before.

Lt. Michael Frank of the Aiken County Sheriff's Office isn't surprised by the findings. He said thieves often take cars in Aiken County for joyrides, stealing them when the opportunity arises, such as when someone leaves a car running to dash inside a gas station for even 30 seconds.

"A lot of crime prevention is common sense," Lt. Frank said. "More automobiles are stolen as a result of two things -- cars being left unlocked and keys being left inside the vehicle. There are two simple precautions people can take to prevent their car from being stolen."

The latest findings come from the National Insurance Crime Bureau, which issues a report on auto thefts annually.

According to its report, the Augusta-Aiken metropolitan area had 2,385 cars stolen in 2007.

The year before, 2,266 autos were stolen, and 2,093 in 2005.

Lt. Frank said authorities often find stolen vehicles abandoned on the side of the road or in the woods, in various conditions.

In Augusta, police have recovered stolen cars from salvage yards, said Lt. Tony Walden of the Richmond County Sheriff's Office.

Thieves can get between $200 and $400 for a stolen car, he explained, which a salvage yard owner can crush and then sell off for its metal.

Authorities are paying more attention to those recycling centers, Lt. Walden said.

As in Aiken County, he said, thieves often take cars for joyriding, and then "they just drive them until they run out of gas."

Most cars in Richmond County are broken into through the rear window and then the steering column is broken, Lt. Walden said.

But authorities also see cars stolen after someone left it running outside.

"They're surprised their car is gone," Lt. Walden said. "They need to be surprised when the joker is still there."