 Coulthard and Button collided on lap 18 when Button attempted to pass the Red Bull on the inside at turn eight ; the Honda lost its front wing and retired a lap later after two pit stops . Hamilton continued his climb back through the field ; he moved from 18th , passing Piquet , Davidson , Sutil and Bourdais in separate manoeuvres , to sit in 14th by the time he pitted on lap 31 . Piquet retired on lap 42 with transmission failure , requiring a <unk> change before the next race . 
