Sat nav units can be worth hundreds of pounds

About 80 systems have been stolen over the last few months in Edinburgh, with two thefts over the weekend in Denny in central Scotland.

The problem has been increasing as thieves cash in on the machines, which can cost between �150 and �600.

Police have urged motorists to take the machines out when leaving their cars.

A Lothian and Borders Police spokesman said: "The theft of satellite navigation systems has been increasing across the UK, however, to date it has not been a major problem in Edinburgh.

Support cradle

"But the theft of car stereos has reduced significantly due to design improvements and the active thief has now turned their attention to sat navs.

"Our advice to owners is to take the unit with you after parking the car and that includes the support cradle and suction pads.

"We would also recommend that owners wipe away the marks left by the suction pads as this is a common indicator to the opportunist thief that the unit itself may have been placed in the glove compartment or under the seat."

The spokesman said drivers should have their units postcode marked and ensure they take a note of serial numbers.

A Central Scotland Police spokesman said: "Motorists remove the system and either leave the holding arm in place or leave tell tale signs that a system is being used in the car and thieves will break into the vehicle in the belief that the system is in the glove compartment or elsewhere.