Police in Pemberton, near Manchester, are urging motorists not to leave satellite navigation devices on display in their cars.
The warning is a response to the fact that seven sat navs have been stolen overnight from vehicles in the area.
Inspector Peter Clarke of the Pemberton neighbourhood policing team advised sat nav owners not to leave their devices, or any other valuables, unattended in their cars "as they are easy for criminals to spot and remove".
He added: "Motorists should also remove the sat nav support cradle and make sure they wipe away any suction marks left on the windscreen or dashboard, as thieves will look out for these."
Other crime prevention tips include marking valuables with your postcode and vehicle registration number, and making a note of the make, model and serial number of any items likely to tempt thieves.
Sat nav devices have been responsible for many motorists ending up hundreds of miles away from their intended destination due to mix-ups over place names.
Written by Stephen Eagle