If you're talking about the formed sheet metal hump that is inside the door, I think you could remove that without any water problems. The black polypropylene (sp?) half moon on the outside of the door has a foam gasket on it that keeps the weather out. The hump you're talking about has a hole in the side with a plastic grommet to run wires through, so it isn't really watertight anyway. I don't know if the hump is welded on or riveted or both so it might be kind of tough getting it off there.
I would say go for it, be careful, and keep us posted!

Brian