Taillght Lenses Filling with Water

[CAC Windsport]

Both my taillight lenses on my 2008 Windsport have about an inch of water in the bottom.
I took them off and the only way to drain the water was to turn them upside down and it drained through what looks like a vent hole in the top.
I assume the vent hole is to allow air in to prevent condensation build up.
However, I believe this must be the source of the water getting in.
I dont want to plug the hole as this may cause issues.
So, does anyone have an idea on a solution to prevent the water from entering and still allow air circulation?

[ducksface]

Install upside down from what they are now.
Or
A small scupper valve
Or
Plug top hole, drill bottom hole.
Or
maybe the headlight fluid has leaked into the tailights because thor used wires too big.

[Hugh.vines@att.net]

I drilled very small hole in bottom and make sure front is tiny bit higher than back when I park