in the 'False Idols' they arrive in LCFR so you have to find it before starting the mission. it's behind the church so it easy to find. when the cars are near the turn to LCFR shoot them with the 'Rocket Launcher'(shoot the limo first before the patriot) then when the helicopter where Faith rides is ready to turn,shoot it again. then go back to father again to finish the mission. If you also failed try shooting the helicopter first,but if you also failed,JUST KEEP TRYING! IT'S SUPPOSED TO BE FUN so DON'T BE IRRITATED! remember what they say: Try and Try until you Succeed!