Drivers have been warned against leaving cars unattended while they de-ice after two were stolen in north-east Surrey in one morning.
The cars, stolen from Park Road, Banstead, and Moberly Way, Caterham, were both left with the engines running to warm up on Monday morning.
A Renault Megane was stolen at about 0640 GMT in Banstead and a Lexus estate about 0715 GMT in Caterham.
"It only takes a few seconds," said a Surrey Police spokesman.
"At this time of year it may seem tempting to start your car to warm it up or de-ice the windows and leave it parked on the driveway," said crime reduction adviser Steve Aylin-White.
"Our advice is always ensure your vehicle is secure at all times.
"Not only is an unattended, insecure vehicle an open invitation to an opportunist thief, many insurance companies will not pay out if you have left your vehicle unlocked."