Thanks @Dippy. so it drains off excess water? @JohnS3 two part job today, touch up the crash bar with black plastidip and fit the honeycomb fog grille covers. As you can see, they look good with the RS4 replica grille but the fog light housings need be painted. Not 100% convinced. Also tested a cold air feed direct to the air filter!
These vents will not drain the water out of the lights as such, but any slight moisture that ends up in the lights will be allowed to escape when the heat from the lights assists its evaporation. I wonder why they added these adaptors to the ends of the pipes, are they known to improve things? I've also got the front of my car, and the lock carrier out into the service position to finally get round to replacing both drive belts, only a year after buying them, now waiting for a low profile M10 Spline socket so that I get the supercharger idler pulley bolt torque just right!
FYI the pipe is labelled "drain hose" in the parts database. Under certain circumstances condensation could build up enough for a pool of water to form.