I had the same issue a few months ago with my Lexus (in rainy Belgium). "Not normal", Lexus said, and they fixed it (by replacing the rubber strip).
With the Tesla S, we're all going to be pioneers (and we must thank the first 10,000 U.S. buyers for already pioneering for the benefit of us Europeans who are getting deliveries a bit later!) so I suppose we must accept that such a revolutionary car, from a more or less newbie brand, will have quite some child diseases. But Tesla must likewise accept to fix them of course! Hence, "normal" is not a correct answer, even is "common" were to unfortunately be an honest answer!