More than 12,000 members have signed up for iRacing's online racing service since it was opened to the public in August, 2008. iRacing uses laser-scanning and other advanced technology to produce tracks that are millimeter-accurate duplicates of their real-world counterparts and race cars of similar visual and mechanical fidelity. The inventory of vehicles currently available to iRacing members features racing cars from Chevrolet, one of NASCAR's automotive partners, including the Silverado, as raced in the NASCAR Camping World Truck Series, and versions of the Impala SS as raced both in the NASCAR Nationwide Series and NASCAR Sprint Cup Series. iRacing has either completed or is in the process of building virtually every track on the 2009 NASCAR Sprint Cup schedule.