Motorists are being advised to secure their cars after a spate of crimes and occasional thefts.
Residents in Haddenham have been warned after thieves stole sat navs, cash and clothing from 15 different unsecured cars in Chearsley, Long Crendon and Oving in recent weeks.
It is thought the suspects are coming to the villages from Oxfordshire after some of the property was recovered in a vehicle in Oxford.
During recent cold weather conditions, two vehicles have also been stolen from Brill and Chilton after owners had left the vehicles running to defrost the windscreens and warm the cars up.
However, thieves took advantage of the unattended cars.
Motorists are advised never to leave their car like this.
If a vehicle is stolen in this way it is unlikely an insurance company will pay out.