the electric aerials use the amp wire to erect the aerial when the system goes on. It sends a small 12v down that to activate stuff.
this 12v is know been pushed into the beesting. I dnt no how it helps, but i would not really bother because most likely when you indicate and stuff you will here it through your speakers as interference will creep thru this into the sound system.
best just leaving it thats what i did still works a treat.