Residents of Oulton Broad, Lowestoft and Carlton Colville have been urged to 'pay extra attention' following a spate of thefts.
Lowestoft police have asked the community to be aware of vehicle security following a number of thefts in the area.
Last week, more than 17 incidents have been reported to police.
Valuable items such as coins, wallets, purses and handbags were taken from the vehicles.
Inspector Liz Casey from Lowestoft Police's Safer Neighbourhood Team (SNT) said: "Valuables left on display in vehicles can also attract attention from thieves. Items such as sat-navs or event sat-nav mounts should be removed from inside vehicles."
Motorists are advised to leave vehicles locked and secure at all times - even if left unattended for only a minute, remove all valuables and personal belongings from the vehicle entirely as audio equipment, sat navs, mobile phones, laptops and handbags are particularly sought after and to property mark valuables.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here