Toyota Speedway at Irwindale is a motorsports facility located in Irwindale, California. It features banked, paved 1/2 and 1/3 mile oval tracks. It is mainly used for USAC sprint car and regional NASCAR races. The 2003 Guinness Book of World Records lists the fastest-ever top speed of a radio-controlled car as 111 mph (178.63 km/h) set by Cliff Lett of Associated Electrics. Lett, a Team Associated professional driver and one of the designers and developers of the aforementioned RC10, set the record with a heavily modified Associated RC10L3 touring car at Irwindale Speedway on January 13, 2001.