Fans at Sonoma were treated to a feast of racing action this weekend. The GT4 America Sprint, GT4 American SprintX, GT4 West, and TC America series each held two races on the support programme for the Blancpain GT World Challenge America. BMW Customer Racing teams enjoyed great success. Eleven BMW cars took the start in TC America and pulled off a sensational top-ten lock-out. Steve Streimer (Rooster Hall Racing) in the #81 BMW M240i Racing was joined on the podium by Toby Grahovec (Classic BMW) in the #26 car and Robert Nimkoff (Auto Technic Racing) in the #20 BMW M240i Racing. This was followed on Sunday by another top-seven lock-out for BMW in race two. This time it was Cameron Evans who took the top spot on the podium in the BimmerWorld Racing BMW M240i Racing. Grahovec was second again, with Streimer third. The opening race in the GT4 SprintX series saw Sean Quinlan and Gregory Liefooghe take victory in both the Pro-Am class and the overall classification in the #19 BMW M4 GT4 run by the Stephen Cameron Racing team. In the Am class, Kris Wilson and John Allen (Auto Technic Racing) finished runner-up in the #16 car. The fastest laps in both classes also went to the two BMW duos. Both pairs finished third in their respective class in Sunday’s second race. Jon Miller and Harry Gottsacker celebrated two second places. They finished runner-up in the Pro-Am category in GT4 West at the wheel of the #28 BMW M4 GT4, run by ST Racing. In race two, their team-mates Samantha Tan and Jason Wolfe finished third in the number 38 car to round off a successful weekend for the team. In the GT4 Sprint series, a total of four top-ten finishes went to BMW on Saturday. In the Pro class, Toby Grahovec finished eighth in race one in the #26 BMW M4 GT4. In the Am class, Henry Schmitt (Stephen Cameron Racing), Dmitri Novikov (Rearden Racing) and Marko Radisic (Precision Driving Tech) came home seventh, ninth and tenth. In the Am class, Henry Schmitt (Stephen Cameron Racing), Dmitri Novikov (Rearden Racing) and Marko Radisic (Precision Driving Tech) finished seventh, ninth and tenth. Sean Quinlan finished third in the Am class on Sunday. Schmitt was fifth, while Radisic and Novikov finished eighth and tenth. In the Pro-Am category of the Blancpain GT World Challenge America, Schmitt and his team-mate Liefooghe again finished seventh. The duo alternated at the wheel of the #87 Stephen Cameron Racing BMW M6 GT3. Schmitt and Liefooghe came home ninth in race two on Sunday.