No one wants to overpay for a car. You haggle at the dealership for the best price. You scout out the best value gas. You get regular oil changes and maintenance so that you don't spend half your life sitting in the repair-shop waiting room. So why would you buy a car that's going to drain insurance dollars out of your wallet?

Car insurance premiums can add substantially to the annual cost of operating your auto. Insure.com has calculated the most and least expensive autos to insure among the nation's 20 best-selling vehicles.

Deric Kaiser of Kaiser Pontiac GMC in Deland, Fla., sells GMC Sierra pickups, one of the least expensive to insure on the list. Kaiser has occasionally seen a new vehicle's potential insurance costs break a sale. "The savvy customer checks it before on the Internet," he has observed. But more often, dealers nationwide say that less than 10 percent, and sometimes less than 5 percent, of their customers will consider insurance when car shopping.

"Everybody takes it for granted that insurance is going to be very similar," says Curtis Walters of Olathe Ford in metro Kansas City, Mo.

If you happen to own one of the above autos, your insurance premium will be different — possibly considerably different, depending on how your personal rating factors (driving record, town and credit history among them) differ from the situation used to calculate average premiums for each vehicle.

Why premiums are lower for these vehicles

Your own premiums are calculated using sophisticated tables combining your personal factors plus the "loss experience" of the vehicles. That means that the owners of some vehicles end up with far fewer or far less expensive insurance claims than others. This "loss history" is used to price other policies and helps keep your premium in check.

For example, if your car model isn't stolen much, your comprehensive premiums may be comparatively lower. If repair costs are low for your vehicle, collision coverage may be lower. The chart below shows exactly where these vehicles have lower-than-average insurance losses (where available).

Top picks

The Chrysler Town & Country is a best-seller not just among families needing to transport children to school and recreation. Junior Brubeck of Jim Clark Motors in Lawrence, Kan., says, "It's not just a yuppie car. It's not just a soccer mom's car. The 2008 is a luxury car." The 2008 Town & Country's rear swivel seats, DVD entertainment system, and rolling-down window in the sliding door make it a popular choice.

"Now for anybody who has children, if they don't have a video they can't go," observes Brubeck. He notes that his buyers research auto insurance premiums more than they used to. Recently he has also had customers who found that their insurance went down after buying the Town & Country. "That gets their attention," he says, and word gets around.

Richard Llewellyn of Palm Automotive Group in Florida has another prime customer for the Town & Country: Retirees who like the Chrysler minivan because it's easier to get in and out of than a sedan, provides them with a seat height to better see the road, and gives them room for taking friends to dinner and golf outings.

The Ford Escape has lots of things going for it in addition to comparatively low premiums, including a new design for '08 and a quiet ride. "It's a very comfortable car with no blind spots," says Walters. His customers "feel safe in it. It's nimble to zoom in and out of parking lots."

Kaiser, who sells the GMC Sierra, has observed that the lines and curves of the truck make it a "very good-looking vehicle." In addition, his customers opt for the Sierra because the trucks hold their value, feature the OnStar system and there are fewer of them made than competitor models, "so 15 other people on your street aren't going to have them," notes Kaiser.

Methodology

Insure.com's list is based on the 20 best-selling autos in the United States according to Reuters News Service as of May 2007.

In order to develop the insurance premium for each of the autos, we assumed a single male driver, age 40, who owns his own home, has a bachelor’s degree and no accidents or driving convictions. The insured works as an administrator in a hospital and drives 5 miles to work one way.

The policy limits for our imaginary driver were $100,000 per person and $300,000 per accident for bodily injury and $50,000 for property damage. Minimum Personal Injury Protection (No-Fault) was included where applicable. The policy has a $500 deductible for comprehensive and collision losses.

Insurance premiums were developed for three different cities, one on each coast and one in the Midwest. Quotes were obtained from four different insurance companies in each city. The insurance cost for each auto was then averaged across all three cities and all insurance companies.