CarMax, a Richmond-based retailer announced the addition of the area’s second store, an event the chain would never have considered a decade ago, according to the Richmond Times-Dispatch newspaper. When the store off Midlothian Turnpike in Chesterfield County opens in late September or early October, it will be the first time CarMax operates two lots in a market of about 1 million residents. CarMax is trying to determine whether a market such as Richmond's can support two stores and how the two locations might affect its market share. The retailer decided to conduct the test in Richmond because the store on West Broad Street in Henrico is the oldest in the chain. Within a 10-mile radius of the CarMax store on West Broad, the retailer has a 15-percent market share – the highest of any of its 50 used-car superstores in 24 markets –and it holds a 10-percent overall market share throughout the Richmond area, said Austin Ligon, the chain's president and CEO. The CarMax store will be close to the Saturn used-car lot and next door to the Pence Auto Mall – two of Chesterfield's highest volume used-car dealers. The 40,000-square-foot CarMax store in Chesterfield initially will stock about 300 used cars but may consider putting stores in Colonial Heights and Mechanicsville in the future, reported the Times-Dispatch. The West Broad store carries about 500 used cars.