A lot of water inside the headlight after a wash indicates to me that the seal between the two sections of the headlight assembly is leaking. This needs to be sealed with silicone sealant or similar. Excessive amounts of water after a car wash cannot be put down to humidity in the air when you think about it. I have the original vents on the rear of my lamps and I have no moisture problems.
Fix the leak for starters and go from there.

 

My headlights are very dry and looks like they are cracking on the top part of the lens, look like skin does when its too dry. anybody know of a product I can buff on that will restore them? and a protectant to keep them that way?