If you have an OnStar service, you already know it can help you out of jams... locked keys in the car, roadside breakdowns. But did you know it can also help cut your auto insurance bill?

GMAC offers its customers in Florida and 33 other states with OnStar a break on their bill of 26 percent and more when they drive fewer than 10,000 miles a year.

Progressive offers discounts to drivers who record their odometer readings with a GPS tracking device.

And with Safeco's Teensurance, parents can program a GPS unit to send an e-mail when the teen's car violates certain conditions, such as driving beyond the speed limit or driving too far from home. Safeco plans to offer users a 5 percent to 15 percent discount on insurance.

Best Buy stores in South Florida have also seen an uptick in customers asking for GPS navigation systems, says a spokesperson, in part because of their potential to cut insurance costs.

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