Here are the top three most expensive states for car insurance and why they are so expensive:#1 Michigan -- Michigan's no-fault insurance structure is largely responsible for the high cost of car insurance in the state. “Michigan auto consumers pay more than most states for car insurance due to the state's high medical mandate. Michigan is the only state in the country that requires auto consumers to purchase unlimited, lifetime medical benefits as part of the auto insurance policy,” explains Lori Conarton with the Insurance Institute of Michigan. “Unfortunately, it's Michigan's auto insurance consumers who pay the price for this unique auto insurance law,” continues Conarton. Michigan, like most other no-fault states, requires its drivers to buy personal PIP insurance. PIP coverage will pay the medical bills of the policyholder as well as any passengers and family members that are in the vehicle at the time of the accident. The big difference is in the amount of PIP coverage that Michigan requires of its drivers. Florida, for example, only requires drivers to carry $10,000 in PIP coverage, while Michigan's no-fault policies must offer unlimited medical benefits, which pushes the price up dramatically. Michigan requires insurers to cover medical claims up to $530,000. The nonprofit Michigan Catastrophic Claim Association (MCCA) covers damages above that amount. In addition to high insurance premiums, Michigan drivers must pay an annual assessment to the MCCA, which in 2016 is $150. The high cost of car insurance pushes many drivers out of the market. According to the Insurance Information Institute (III), an estimated 21 percent of Michigan drivers were uninsured in 2012. High numbers of uninsured drivers raise rates because there are fewer drivers (and their premiums) to share the risk pool. The high cost also leads to - while technically legal - unscrupulous behavior. Some Michigan drivers will purchase a seven-day policy (which insurers in Michigan sell) so they have proof of insurance when registering their vehicle and then let the policy expire after a week, leaving them uninsured.