That looks like a 318iS aircleaner intake. I have removed the one on my 318iS and blocked off the inlet on the aircleaner housing and made a hole in the housing on the side facing the grille. Then removed the fitting that clips onto the section behind the grille and modified the plastic ducting to make it fit the new hole in the aircleaner. My theory was to get a more direct airflow into the aircleaner housing. So i have that pipe no 3 lying around here but the end where it has the clamp is also slightly torn, which isn't a crisis as it is just a duct for the air to the airfilter housing.