Car thieves have developed a new way to steal vehicles in West Yorkshire by simply picking them up and loading them onto lorries.
Motorists are being warned to be vigilant about where they leave their cars after an increase in thefts, particularly Audis, VWs and BMWs.
Police said it is easy for thieves as there is no need for keys and alarms are not activated.
The number of other car thefts in the county has also increased.
Immobilisers overcome
Pc Colin Whiteley, crime prevention officer in Dewsbury, said: "We have had several reports over the last few weeks of cars being lifted off the ground onto the back of low loaders which are then just being driven away.
"Obviously there is no need for car keys and no problem in overcoming immobilisers.
"I would like people locally to be aware of this issue and be on the look out.
"Being a victim of crime can be very distressing and we want to reduce opportunities for car thieves as much as possible."
Over the weekend, 17 cars were broken into and stolen by more conventional means in the Gomersal, Birstall, Carlinghow, Dewsbury Moor, Thornhill, Batley, Ravensthorpe and Norristhorpe areas.