In a parking lot brawl match irish whip your opponent into all the dials on the firetruck then grapple them, you will hit their head aganist the dials and then the ladder on the firetruck will swing out. To get up there get up the side ladder and then press triangle, once up there press square to jump or X to get off. To kick someone else of there just wait until they're up there and then climb up the side ladder and press triangle to climb up the ladder and you will get there and throw the opponent off in a perfect position to jump on.