Water in window frames

[MMulcahy]

While washing my rig last week i noticed that water streams off the back cap and goes right into the window frame of my back window. The window itself is about an 1/8" out from the body, and it looks like the water (or at least some of it) leaks back out from the bottom of the window.

I examined my other windows and they too have a small gap between the window and the body. I haven't seen any evidence of water inside the rig.

Is this normal? Should i be caulking all the window seams? No one at the dealer of otherwise has ever mentioned that buyer seam caulking is required.

thanks for your response.