Though this is common sense, it may be worth a mention during your next driver´s meeting: unattended cars left idling to warm up during cold weather are much more likely to be stolen. Across the country, statistics show that as the temperature drops, car thefts rise.Drivers often don´t heed this warning because they only leave their cars unattended for a minute. Yet, for instance, police in Stanislau County, Calif. say many thieves cruise neighborhoods on foot or on bicycle in the morning in search of that white cloud of smoke coming from the tailpipe. "I´d say we´d save three to four vehicles a day from being stolen without the warm-ups," Greg Peck of StanCATT, the Stanislaus County Auto Theft Task Force, told The Ceres (Calif.) Courier.Tacoma, Wash. police detectives are trying to stay one step ahead of the car thieves. Police will issue a warning or even a ticket to an idling vehicle left unattended. Each year 3,000 cars are stolen in the Tacoma area with 10 percent due to idling, according to a Tacoma television news report.Police in Denver even have a name for that type of theft-opportunity—“puffers.” Of the 11 cars stolen on a recent Sunday in Denver, seven were puffers, according to a report in the Denver Post. Like Tacoma, Denver residents who leave their cars running unattended face a traffic citation and a fine, according to the report.