Insurers are also starting to introduce optional "telematic" devices, which, once installed on a vehicle, collect data about your driving habits for the insurance company. You get a discount for agreeing to use one, and your rates are based on your driving habits.
People who drive less and drive slower might have lower rates than people who drive a lot at high speeds, for example.
"From the insurer's point of view, these things are meant to reward and isolate those low-risk drivers," he said. "You're signing up for the prospect of a discount."
Credit. You wouldn't think your proficiency at paying bills would have anything to do with whether you'll crash your car, but auto insurers insist there's a link. Drivers with problems on their credit reports are more likely to file claims, they say, and are charged higher insurance rates in states that allow tying rates to credit.
"Credit has become, in the last 10 years, a very widely used and fairly significant part of the calculation of what your final price will be for auto insurance and home insurance," Fults said. "It was introduced in the 1990s and has slowly been incorporated into every carrier now."
Carriers aren't so much looking at your three-digit credit score as they're looking at the stability and good standing of your relationships with creditors, Fults said.
Still, there's a correlation with scores. A CarInsurance.com study showed that drivers with credit scores over 750 save an average of $783 a year compared with a drivers in the same age bracket with average scores.
Check your credit report once a year for free from each of the three major credit bureaus at AnnualCreditReport.com.
Discounts. Make sure you're getting all the discounts you're entitled to — for driving low miles every year, for example. A teen driver, who can raise rates 50 percent, can get a discount if he or she has good grades, typically at least a B average, Toups said.
Taking time annually to review your coverages with your insurer will make sure you're getting those discounts, Fults said. You'll not only incorporate your life changes into your auto insurance, but you'll learn about the insurer's new products and pricing, which change often.
Drop collision. It might be worth dropping collision coverage on older cars that aren't worth much. Consumer advocate Clark Howard said the time to consider dropping collision is when cars get to be about eight years old. His rule of thumb: If your annual, not monthly, premium for collision and comprehensive is more than 10 percent of your car's value, remove collision coverage and just pay the liability premium. Find your vehicle's private-party sale value at such websites as kbb.com, edmunds.com and nadaguides.com.
Did you know?
Similar to a credit report, you also have an insurance-claims report. It can affect whether an insurer agrees to issue a policy and what rates you pay. To see what insurers know about your claims history, get a C.L.U.E. It's your free, annual auto and personal property claims reports by the Comprehensive Loss Underwriting Exchange. Get it once a year online at personalreports.lexisnexis.com or call 866-312-8076.
Resources: Sampling of online resources about auto insurance: http://www.insureuonline.org, iii.org, insure.com
Average cost: Average auto insurance expenditure per vehicle for select states:
SOURCE: National Association of Insurance Commissioners, 2008 data