OSWEGO, Ill. (CBS) — You’ve heard of thieves stealing car parts like catalytic converters, but now there’s something new.

Thieves looking to cash in are taking pickup truck tailgates – yes, just the tailgates.

CBS 2’s Kristyn Hartman reports.

Leaving a pickup tailgate unlocked might very well be an open invitation for theft. But Oswego police say it’s happened six times in as many months. It happened once at the Hennessy River View Ford lot.

It turns out that they’re worth a lot of money.

Sales consultant Rich Voight says tailgates typically take a beating. To replace one at a dealership is expensive, and someone who steals one can offer a deep discount but still make cash.

“It’s a $4,000 item that somebody sees brand-new for $600 or $700 they’re going to buy it, and it’s virtually untraceable,” he says.

There is a way to stop a thief. If you lock your tailgate, they’re virtually impossible to steal, Voight says.

He and his co-workers walk the lot each and every night to check each and every tailgate.

Oswego police say all the trucks targeted have been newer model Fords.

Thieves took the tailgates from pickups parked on lots and personal driveways.

One more tip: If you can’t lock your tailgate, park the back of your truck close enough to your garage so that thieves can’t pull the gate down.