Fair question. The article attached seems to indicate metal roof rails - hopefully for the Model S. 3rd paragraph.
Tesla’s massive parts distribution center in Lathrop, CA is nearing completion
Hopefully, it's true. Opened mine up yesterday for the first time this spring to get some extra fresh air and if I consider getting another Tesla, I'd really want it. This might be the same case as the cooled seats - was there, taken away and improved and then brought back.