More than a dozen such incidents have been reported since last week in Newmarket on Fergus, Kilmaley and Ennis. The most recent thefts from cars occurred on Monday night in Cratloe.
An Garda say they are following a number of lines of enquiry.
Meanwhile, a public warning remains in place regarding a silver 2004 Ford Mondeo car, with Cork registration plates, which has been spotted in the vicinity of at least some of the recent break-ins. Members of the public are requested to contact their local Garda station with any information about the car or its occupants.