Casey Mears , meanwhile, is rumored to be out of the No. 5 Chevrolet at Hendrick Motorsports and could join Richard Childress Racing, which plans to add a fourth car in 2009. That opens the door for veteran Mark Martin — who is sharing the No. 8 Chevy with youngster Aric Amirola at Dale Earnhardt Inc. this year — to take over the No. 5 car, or to reprise his mentor role at ...