On my '51, I just noticed a couple of water tracks, inside the cabin, at the headliner J rail, drivers side. I don't remember what the factory did to seal that joint, where the roof and sides come together. But I'm going to have to remember to run some sealant down the full drip rail before I do final paint. Maybe I sanded too much paint out of there when I stripped it? As far as I can tell, the roof panel sits on top of the side panel rail that has the drip rail. Might have been better if they had made the roof panel with the drip rail lip that attached to the side panels. Ah, but what do I know.......