Dirt Cast
Donnie Roberts & Collin Thirlby – UMP Modifieds / Michigan Dirt Cup Allstar Performance Modified Tour 4-7-11
Michigan Hall of Fame driver and now car owner Donnie Roberts of Gladwin, MI and his Rookie UMP Modified driver Collin Thirlby of Traverse City, MI joined Dirt Cast to talk about their racing careers, how they came together, UMP Modifieds, the Michigan Di