[Ishler]

I had a 2005 3670 that had a bedroom slide leak when new. If you look along the bottom of the slides in your picture you see a trim piece with a vinyl screw cover strip. The factory replaced that piece(on both sides) with a 90deg piece (like angle iron) and screwed into the side. Apparently water gets behind the screw cover and channels into the slide. All of the newer units were built with the newer trim.