... why would my in boot fuel tank have a 4 Mtr long breather pipe off of it? I vent by the return and then goes into the cabin round by the roof and under parcel shelf on a 4mtr loop before exiting by the exhaust in the N/S rea wheel arch?!?!?

Why so long?
I have seen the breather just vented into the filler neck before now, I think Reyland on his Pro alloy tanks, is this better or more adviseable?