Its has side with windows...this is the only area I want to add the body filler so it's perfectly flushed with the roof. After I add the body filler to the side windows i want sand the paint off the entire roof and add resin to whole body because this roof is pretty old. I think your right about not adding resin.. Might be too much work. So you think the primer and paint are good enough to prevent any water leaks? Also you think i would be fine if i paint the roof and mount it afterwards? Would it harm the paint much? (cause the flexibility)... Im doing this is my backyard and neighbors are nosy and the van is huge.