Aye tevie,
High up under the seat, with a "U" bend so that water can't flow down it, or trail it out beyond the back wheel and zip tie to frame. Final alternative is to form a "U" bend and insert into a vented container (quirky comments/containers de rigour on race bikes!).
Have a look at old race bikes, if my description is a bit off.
I would suggest that you don't put a K&N filter in the end as they tend to increase crankcase pressure, inspite of what K&N say and you are liable to produce leaks from joints and mating faces that never weeped before.
Good health, Bill
