The most successful season in the 31-history of Sopwith Motorsports came to an end last weekend with two first-place trophies at Tulsa's  Hallett Motor Racing Circuit.   In a joint effort with Shaky Dog Racing on Saturday and Sunday, the team participated in the GP2 division of the World Racing League's October Rush sports car endurance races. The McGunegill Engines/Boschett Timepieces/Impact Racing Mustang started midway back in the 29-car field in Saturday's nine-hour enduran...