An article was published in the Indian Economic Journal that demonstrates the economic harm of price regulation of the auto insurance market.  The article shows that auto insurance rates and rate instability are higher in more regulated markets.  In addition, there is no evidence that the market has insufficient rivals to achieve competitive prices, that industry profits are above modest levels (compared to other industries), and that price regulation leads to lower profits.  In fact, the empirical evidence in the article demonstrates that more regulation leads to higher costs and higher consumer prices.  The article can be downloaded here and its citatation is:

Joseph P. Fuhr Jr. and Stephen Pociask, “United States Private Passenger Automobile Insurance Regulation: An Analysis of Industry Structure, Conduct and Performance,” The Indian Economic Journal, Volume 59(2), September 2011, pp. 51-74.