It's valuables like a purse, credit cards, and especially GPS units that thieves are looking for, and summer is prime time for break-ins. That's why Springfield police are warning drivers to double check the way they leave their cars and what they leave in them.

"The problems we are having is people leaving their vehicle with numerous items in it for the would-be thief, making their job a lot easier," said Detective Richard Goodreau of Springfield's Police Department, Auto Theft Unit

Police say since April 1st, there have been 237 break-ins. From those, 49 GPS systems, 16 laptops, 34 radios, and 12 I-pods were stolen. And it might not be safe enough anymore to put valuables in your trunk.

"People open up their truck, put their stuff and and then they leave. There's nothing to say there's someone there looking around," said Det. Goodreau.

Instead, try to bring what you can inside with you, and wipe down windshield markings from a suctioned-cup GPS or radio. And make sure to have the serial number of your GPS.