Buxton police are urging residents to remove valuables from their vehicles after several were targeted in the town.
One crime happened overnight between Monday, July 10, and Tuesday, July 11, when a Vauxhall Astra was parked in Windsor Park Road.
A thief smashed a window to steal items from inside the car.
Police understand that other vehicles were targeted that night, although not all owners have contacted police.
A Derbyshire Constabulary spokesman said: "Drivers are being reminded to make sure that they remove items including phones, wallets, sat navs and bags from display and to park in garages or well-lit areas where possible.
Witnesses or anyone with information should call PC John Keys on 101, quoting reference 17000293755, or contact Crimestoppers on 0800 555 111.