Police in Barnsley hope to drive down car crime by looking for vehicles at risk of break-ins.
Officers in the town ran a three week operation focusing on Hoyland, Wombwell and Darfield.
They carried out high-visibility patrols between midnight and 5am – the times when most offences have happened.
Officers in plain clothes were also deployed on the streets in a bid to identify thieves.
Police Community Support Officers looked for vehicles left unlocked or with valuables on display and found over 30 at risk.
Known offenders, with criminal records for car crime, were visited to inform them of the operation.
Temporary Detective Chief Inspector Steve Handley said: “The operation has been a great success across Barnsley. We’ve gone from around six or seven vehicle crimes a day to one or, on some occasions, none.
“We’d urge all vehicle owners to take care of their property and not to leave money or valuables on show.”