somethign thats been bugging me a while

, in the boot in the rear corners (effectivly where the air vents/sunroof drains go into) on the pass side i get water in there

the driver side does not???
anyone else have this??
i thought it may be the roof rails so i did have the driver side off a while back and sealed it.. could it be the rail on the passenger side too?? As the sunroof drain is in the vent both sides and i cannot see where else it could be coming frm???