After a heavy rain or going through a car wash, I generally hear water sloshing around in the back my '93 del Sol, around the rear window. This ends up allowing moisture into the trunk which I have successfully blocked with a few spare diapers.

I believe that are some drains under the compartments in the back there--perhaps those are clogged? Is it normal to have water drain through the back window assembly?

I'm wondering if some water also gets trapped in that window assembly too, only to leak out slowly. In any case, I'm wondering if this is a common experience or what. I can especially hear water moving when going around a corner when it happens.