'64-'66 Abody Cowl-How did Factory Make it Water Tight?

GM removable cowl panels are nice, but they screwed it up with their "flush and dry" rocker panels. Yeah, the water can get into the rockers to wash them out, but so can leaves and pine needles and dirt, and all that turns into a nice sponge when the water hits it. My Corvair rockers were wrecked right at the intersection of cowl and rocker.