installing seals on the roof rail, what type?

Under the stainless I have always used a vinyl foam weatherstrip available at most hardware stores. It is made for use around doors and windows in houses but I've had good luck with it. it has adhesive on one side so just peel off the backing and stick it to your stainless. It comes in all widths and thickness. The new weatherstrips do seem over size. i always start at the front and put the weatherstrip in the channel car side first and then work the outside lip into the channel using a wood paint stick. Just work it a couple inches at a time. It takes a while and a few swear words but it should go.