Jeremy, looking at it from a visual stand point rather than from a factory correct paint option, I would think the your shirt only goes down to the "belt line", where the belt outlines the separation of the shirt and the pants. So using that human fashon statement, I would think that the paint falling from the roof would end at the belt line as Tim and Vern mentioned, not into it. A pin strip down the middle of the belt line matching the roof color will serve to tie the upper and lower colors together thus topping off the purpose of the "belt line" in the first place.
Denny Graham