Car insurance is one of those non-negotiable things in life. If you drive, you really should have auto insurance, not only to protect the money you've put into your vehicle, but also to protect yourself from lofty medical bills and payment for damages to other drivers or property owners.

Your auto insurance rates are subject to change depending on any number of factors. Accidents or claims can certainly increase your monthly payments, but there are other factors you may not even think of that can push that number higher than you'd like.

Steve Pape, insurance agent for Midwest Insurance Group explains how base insurance rates are set for a specific area:

Each insurance company divides the states that they cover into territories. Each territory is given a number. Base rates are often calculated using historical traffic and accident data. If there are an unusually high number of collisions in one territory, for example, the liability and collision premiums for that area will be greater than a territory that has a history of very few collisions. Insurance companies want to contain costs in each area. An actuary leaves almost no stone unturned when it comes to compiling statistical data on drivers and vehicles.

With all the confusing data research done by insurance companies, you can be prepared for unexpected changes to your policy. These are just some of the many factors that can change the cost of your auto insurance coverage.

Multiple Warnings

You know what it's like; flashing lights in the rearview mirror give way to the officer greeting you. After some nervousness and exchanged words, the officer tells you that you'll be getting a warning, this time. But can these warnings add up to a higher premium?

"The vast majority of insurance companies do not look at speeding warnings as surchargable," said Pape. "However, speeding warnings often come into play when you start with a new insurance company."

When your insurer assesses your record, two tickets in four years may not look terrible. But, when partnered with two warnings, you could look like a habitual speeder.

"This could affect an insurance company's willingness to offer coverage in their premier rating tier," he said.

Getting Married

Getting married can be full of blessings. One may even come from auto insurance companies.

"For a young couple, getting married provides a nice discount to your auto insurance rates," said Pape. "Provided that your new spouse doesn't have an adverse driving record. His/or her bad driving habits can have an effect on the rate or may cause the household 'safe driver discount' to be removed from the policy."

Having Kids

Kids add all kinds of expenses to life; medical bills, food, clothing, entertainment and more. Auto insurance isn't one of those places where you should expect an increase.

"If you have children, your rate shouldn't go up," said Pape. "If you have children who are driving, expect to pay much more for your auto insurance as young drivers are indeed inexperienced drivers."

But, having a child who can drive doesn't mean your rates will go sky-high. Many insurance providers offer "good grades" incentives that can offer parents some relief.

"One thing to keep in mind is that a child can only be listed as an 'occasional' driver when there are (more) vehicles in the household than there are drivers," said Pape. "If you have three vehicles in the house and three drivers, then there is no occasional driver, and companies will consider your child a full-time driver."

Natural Disasters

Tornados, floods, hurricanes, earthquakes and other natural disasters can do more than wreak havoc on homes and properties, they can also increase insurance rates.

"Natural disasters often do affect insurance rates," said Pape.

He explained that, if an insurance company insures a large percentage of people in an area that is ravaged by tornados and high winds, the company will have to pay out considerably for damages.

For example, individuals who live in "tornado alley" can have higher rates for auto coverage than people who live in areas with low-incidences of tornados or natural disasters.

Will moving (company or home) increase your rate? Moving from a small town to a large metropolitan area will bring an increase. The reasons? Higher volume of traffic, complex interchanges, and heavy rush hour traffic increases the likelihood of accidents.

Multiple Claims

A bad month or year can have an impact on your policy's bottom line. If your auto is broken into multiple times, your comprehensive coverage will increase.

"The insurance company is going to want to know why your vehicle is becoming 'easy pickings' for break-ins," said Pape.

"The first time or two there may be a broken window and some missing property from inside your car," he said. "The next time it might be the entire car that is stolen."

Your Credit Score

Credit scores are used differently across the insurance industry.

Pape explained that some companies use credit scores for determining discount rates, while others use it to determine which rating tier a driver falls into.

"In determining rates, your score is used in conjunction with your claims history, driving record, and other factors," he said.

How To Get The Best Rates

The best way to get good rates is to shop your insurance every few years to make sure you're getting a decent rate and good coverage.

Pape provides tips:

• Find at least two independent agents and a few select captive agents -- or agents who work with only one company
• Provide the agents quoting your policies with copies of your coverages, drivers license numbers, VINs and any loss history that you can recall
• Shop your insurance as a package -- compare auto and home/renters insurance together.
• Ask what endorsements or riders are available and ask about the costs associated with different payment plans as policies that are paid in full are often discounted as well.