I think the title says it all. The hose that runs from the puke bottle out to the rear fender, is it needed? Looking at my fender removal and I'm trying to figure out if I need it and where I'll stuff it if I do. If not, it'll get added to my soon-to-be growing box of stock junk.

 

When the radiator vents to the bottle, the air in the bottle needs to go somewhere. If the bottle overflows, that needs to go somewhere too. Better to go somewhere other than all over the bodywork..

Route it somewhere where it won't cause problems.