My wife and I were at the cinema last night and we were discussing how fortunate is was that we arrived early for a packed session. I said: "Otherwise we'd have to sit up the front." She said: "You mean down the front." I said: "Well if it was a plane, you'd say up the front." And she pointed out that, because of the rake of the seating, "down" was definitely the right word. "It's so down," she said, "that you have to look way up and hurt your neck."
PS: It reminds me of a story my father used to tell about a European immigrant who couldn't understand why, in English, we speak of chopping a tree down when it is up, then chopping it up when it's down.