Open Track Challenge runs a "full season" of racing at 5 tracks in a single week: Willow Springs, Thunderhill, Sears Point/Infineon, California Speedway, and Arizona Motosports Park.. Two division are run, Touring and Unlimited, and a stock production car can be run with nothing more than a mounted fire extinguisher, two drivers, and the $1700-$2100 entry fee. For Touring the car MUST be driven from track to track between races, up to 450 miles distance in a day.