Why do Class C's always leak in the front upper bunk area?

My 09 Cambria has the entertainment center up front instead of a bunk. During a windy rainy trip I had a few drops on the inside of the windshield. I have tried to duplicate by spraying with a hose etc. and have yet to find the reason. Wondering if it wasn't just condensation forming on the inside and running down.
As far as the construction, I have had to repair the brackets that hold the nose to the roof/cab of the chassis a few times already. I watch how much it moves while traveling and it's just a fiberglass cap.