Broken plastic line/tube identification needed.

Hey guys. So I couldn’t get any pics to upload at all. But! I did find a pic of it from this forum. Please see the following link.

http://audirevolution.net/forum/index.php?topic=3344.0

If you look at the second post, it has pictures. Look at the first pic. Above that main shaft wheel pulley, there is a metal tube. Clipped to that, right above that metal tube is the black plastic line I am talking about. It is broken. I do not know what it does or where it goes. I tried to feel it and it goes somewhere behind the bumper on passenger side towards headlight washer area. Anyone have an idea of what this line is?