As executive director for Publius, a voter-education nonprofit in Michigan, Vincent Keenan got well acquainted with an odd phenomenon in his hometown of Detroit: A troubling number of residents aren't registered to vote in the Motor City. The reason has nothing to do with citizen apathy. Instead they are registered to vote in the suburbs, where car insurance is cheaper. They use an address outside the city to renew their driver's licenses and register, then report that address to insurers. (See "Where the insurance cheaters live.") "It's an amazingly pervasive piece of information about living in the city of Detroit that people pick up on incredibly quickly," Keenan says. "It is effectively a poll tax." The impact on voter registration is just one of the consequences of the city's sky-high car insurance rates. Another: Lots of folks don't buy insurance. Michigan has one of the highest uninsured driver rates, with an estimated 19 percent of motorists going without insurance, according to the latest Insurance Research Council study. But estimates for the uninsured rate in Detroit are even higher. In a commentary for the Coalition Protecting Auto No-Fault, Melvin Butch Hollowell, former Michigan insurance consumer advocate, put the number at 60 percent.