I have a damp patch on the wall panel directly under the offside lower corner of rear window. All seals look ok. Anyone experienced this ?

Could it be a build-up of condensation due to lack of ventilation, reading that the seals seem to be ok.

Upper brake light is a known failure point so that water then tracks down and into that area. It’s a simple job to remove it which may then reveal whether it is the culprit. Resealing it should be simple with the correct sealant.

Ah, will definitely try. Many thanks.

Good luck Bilko. 🤞
Once water is in it will track downwards in all sorts of pathways so where it appears internally may be nowhere near its entry point.

I had same problem it turned out to be the window seal but also had the brake light changed and re-sealed, belt and braces