Outside it's another sizzling day in Phoenix, with triple digits in the shade, and CSK Auto Inc. CIO Larry Buresh wishes it were hotter. "Extremes break cars," he says. "Extreme heat, extreme cold. In this business, you hate moderate weather." CSK is one of the largest auto parts retailers in the country, a publicly traded company that grossed $1.6 billion last year from its three brands: Checker Auto Parts, Schuck's Auto Supply and Kragen Auto Parts. The automotive aftermarket is a $110-billion-a-year business--a tough, low-margin space dominated by a few midmarket firms and a larger rival, AutoZone Inc. Last year, CSK's sales were essentially flat; in the company's annual report, CEO Maynard Jenkins admitted that 2004 had been "a challenging year" for CSK.