After years of declining or staying the same, auto insurance rates are now headed in the other direction. Allstate and Progressive are both raising premiums aggressively in 20 states, according to Bloomberg. There are a few factors contributing to this reversal. First, the availability of Internet insurance quotes sparked a battle for market share that has exhausted many of the insurers. Now their focus has turned from stealing customers to making more money for their own stockholders through higher premiums. Meanwhile, The Wall Street Journal reports that insurers are suffering more losses in collisions as people buy cars with greater horsepower. More horses under the hood increases the level of accidents as people drive more aggressively and speed. The conventional wisdom about calling your insurer to find out what it will cost to insure a car before you buy is again great advice. Plus, it's even more important now than ever to shop insurance rates.