Hi Iain, Been reading this thread with interest, The area's of damp you have shown on the photo are typical on these model van's,the most likly area's of ingress are the top rail, rear high level brake light, running light's, and awning rail, what you need to do is remove the parts listed,(when you do this it's usually evident where the water is getting in) clean off all the old sealer, resal with IDL99 or similar,and refit,the problem is when you've sealed the damp area's and try to dry the van inside is that there is nowhere for the water to go, so what we tend to do is in a locker as near to the damaged area's as possible is fit a circular press in vent(available from caravan outlets)you need to remove the wallboard with an hole saw of the corrct size then fit the vent, then with all the doors and lockers open run a small fan heater, you need warm moving air. unfortunatly this will not remove any staining that may be on the panels.