P38A Upper tailgate.

After any decent amount of rain (truly significant or otherwise) it is often the case that when opening the upper tailgate water begins to drip out of both of the corners of the lower edge.
I noticed the other day that where the number plate lights are exposed through the bottom edge of the tailgate there are indications of tin-worm beginning to take hold.
I expect it is a common problem, does it have a common cure, or is it like the common-cold and just something to be suffered? I suspect the water is just running down the glass and getting in past the lower rubber trim but I would appreciate any known causes/cures. Otherwise I shall just try some sealant. after cleaning it out.
I would be grateful for any wisdom and experience of a proven "fix".
All help/advice is much appreciated as always.

Mine does it too..

I've just learnt to not stand under the drips

Sprayed as much of the inside as possible with Wax Oil on mine.

Drill some more holes!!!
Waxoil is a good idea... Tons of it..

Only place water can get into upper tail gate is by running along the harness connection to the body i would think. Check the rubber conduit is not split or misplaced.