Hi Chap.
The damp in the boot on my PRHT was actually caused by the deck seal. It needed removing, cleaning, resealing.
I too park back end down, but since checking the drains (mine were fine, pouring hot water through them confirmed good flow) and cleaning any drains/seals around the rear windows and doing the scuttle seals, all is now well.
Mine’s a daily drive and has dried out nicely. No condensation in the cab.
Good tip on the drain cover removal btw.
Rick.
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