Hi all. I thought I would start with this one. After looking at alot of GU patrols, It seems like a common issue.

If you open up both rear barn doors, then look up towards the rear roof of the car, there is a black rubber seal. It is mostly a lip seal with two balck plastic"scrivets"? holding it in place. It would pay to pull back the seal and have a look at the lip it joins to and check for rust. Mine is just starting to go, but have seen some real bad ones where the lip has mostly gone.

cheers Pete

Had it fixed on mine already. Seen it wagons with 40.000km on them. Thanks for the heads up Pete anyway