Did you acquire a dog guard as well? If so how does it fit? I am in exactly the same boat having just bought a RX 350 SE-L and, though a "cheapo" guard I had previously will do short term , it isn't a great fit.
I just wonder how the Lexus guard fits, given the contour of the roof where there is a drop (LHS facing) presumably for the rear tail motor. This means roof is lower left side than right. As all guards I have ever seen run straight across, this means that either you have a large gap to roof, or cannot extend bars to left hand side.
Anyone advise?