"He who marches out of step hears another drum." ~ Ken Kesey
Not to piss in your corn flakes, just an observation here, take it for what it's worth. Your seams are going the wrong way. they *should* be vertical panels starting from the back of the vehicle. If you do decide to panel horizontally, you want the overlap the other way, so it's on TOP of the bottom panel so it doesn't create a "shelf" for water to sit on. You may see this fail prematurely...just sayin...