water leak back seat 1.2 corsa 02?

hi when it rains heavy i have water coming in somehow underneath back seat (passenger side) have taken the seat out and the cover and under neath there is a electical cable in the well of the seat which seems to hold the water making the backseat soak it up it also seams to be running into the boot .have put a hose pipe on but cant seem to find were its running seems to be coming between the padding as roof isnt wet from inside any body got a clue if its a say a rubber seal or what gordon