Stars from all makes of racing will be on display Saturday, leading their respective classes to the green flag the Mobil 1 Twelve Hours of Sebring.Several former race winners from America's top motorsports series earned poles Friday for the season-opening American Le Mans Series event held at Sebring International Raceway.A pair of open-wheel standouts went head-to-head for the P2 class pole with eight-time IndyCar race winner Ryan Briscoe in a HPD prototype earning the top spot, edging reigning IndyCar series champion and teammate Ryan Hunter-Reay. Briscoe - who also has three career ALMS wins - is competing this weekend for Level 5 Motorsports.The 2011 NASCAR Sprint Cup Series rookie of the year Andy Lally earned the GTC class pole, in a Porsche 911. Actor Patrick Dempsey is Lally's co-driver, and Dempsey and Italian soccer star Alessandro Del Piero own the Dempsey racing entry along with Joe Foster, who also co-drives.Lally is a multi-time winner in both the American Le Mans Series and GRAND-AM, winning championships in the GRAND-AM Rolex Series three times.Colin Braun, who competed regularly in the NASCAR Camping World Truck Series and NASCAR Nationwide Series between 2007 and 2010, earned the PC class pole in an ORECA prototype. He has one career truck series win and 39 top-10 finishes between the two series.The overall and P1 pole position was claimed by Marco Fassler, driving the No. 1 Audi Sport Audi R18. Gianmaria Bruni earned the GT class pole in a Ferrari 458.