Ive routed the wires along the rack itself towards the back of the vehicle and routed them in through the back door seal and fitted a waterproof quick connector.
Next route the power wires from the battery box behind the trim pannels or under carpets to keep it neat and tidy.
Attached the female water tight connector to this and mounted this on the rear door panel with a couple of screws behind the door seal.
That way you have a quick release fitting if you need to take the rack off, no holes in roof etc...nice and simple!