We've had ours looked at by the US customs in Detroit and they never asked for the slides to be opened. I stood outside on the sidewalk and was asked not to put my hands in my pockets after I unlocked the door for them. One apologized for his boots being dirty. We've crossed the border many times and never had to have the slides open on either side of the border.....I might just have jinxed myself :). I'm pretty sure when they ask you questions other than the usual they already know the answers from looking at their computers. Last week they asked how many times we enter the US as he was staring at the computer. Have your ducks in a row, don't be carrying something that will get you into a lot of trouble and maybe call the customs at the point of entry and ask just what you can bring into the country you're going into. I do, because things change from time to time. Just be prepared to do what they tell you to do.