Here's my last pic on this.
I don't know if you can see it or not, but there are 2 one inch
slots for the water to drain out of the window channel. In the
case for the back glass though, is the pane is outside the weep
slots. Wife was determined to find where the water had come
from. We've had 2 or 3 torrential down pours the last two weeks.
She disappeared and then reappeared with the garden hose and
while I watched she hosed the outside down. That's how I found
the water entry on this occasion. With the down pour, wind at just
the right angle, and the trailer tilting to the right (ground not level),
water made it's way in through the weep holes. I've got some rope
caulk I may be using on occasion to solve this little dilemma.