THIEVES are targeting the latest must-have satellite navigation systems.
Criminals have stolen more than 150 of the high technology systems from cars in West Yorkshire - including several in Huddersfield - since the beginning of May.
Now motorists have been urged to take them out of their cars when they are parked.
In Huddersfield, police have had success against the thieves, arresting two men for a spate of thefts of satellite navigation systems.
They were given drug testing and treatment orders by the courts.
Det Con Russ Conlon, of Huddersfield police's intelligence unit, said: "The problem is that satnav systems are the latest technology and so are more saleable than cassette or CD players."
West Yorkshire Police's crime reduction officer, Det Insp John Minary, said: "The message is simple. Motorists need to help us to help them.
"Don't leave satellite navigation systems in unattended cars. Take them with you when you leave your vehicle.
"The security feature is that they are portable. They are not designed to be left in unattended vehicles.
"Drivers often think it is just a problem in car parks, but many have been stolen from driveways and from cars parked outside homes.
"Don't hide them in the glove box and if you have a garage, use it.
"These systems are very attractive to thieves. They are easy to steal and very easy to sell on."
He added: "The systems cost up to £700. They are expensive to replace, including damage to vehicle windows, and costly in terms of your vehicle being off the road."