Burglars are targeting South Holland homes while occupiers are away to steal the keys for luxury cars.
Police Insp Jim Tyner said the offences are “part of a national series”.
A blue Mercedes E-series 250, registration number AO60 FTD, was reported stolen on Sunday following a raid on a house in Spalding’s Pinchbeck Road.
Anyone who has seen the car or saw any suspicious activity at the house is asked to call Spalding Police Station on 101 or the national crime-fighting charity, Crimestoppers, on 0800 555111.
A Porsche 911 was reported stolen on Saturday by residents of a property in Station Road, Surfleet.
That car was recovered by police in Peterborough.