Motorists in Wrexham can now place stickers on their windscreens to let police know that the driver of their car should be over the age of 25.
Police will be able to tell if a young driver should be at the wheel
It is part of a crackdown by North Wales Police on car crime by the young.
Officers say research shows that those in their late teens or early 20s are most likely to be behind road crimes.
Police are handing out stickers with the number 25 printed on them to show the driver of the vehicle should be 25 or over.
If police see young drivers behind the wheel of a car displaying the sticker they will stop them and check the vehicle.
"Car crime is an ongoing problem we are committed to tackling in partnership with the community," said Sergeant Jim Staunton.
"Analysis has shown that most vehicle crime is likely to be committed by someone under the age of 25.
"If this means criminals think again about taking a vehicle then I will see it as a success," he added.
However, civil rights group Liberty have said they have concerns about the scheme.
"If you're a 27-year-old driver, how will the police decide if you're 27 or 24?," said a spokesman for Liberty.
"I am concerned that this will discriminate unfairly against young people," he added.
The pilot scheme, which has been welcomed by local county councillors, is being carried out for six months in the Wrexham south area.
If successful it could be extended throughout the county.