At the moment when spotting Aliens inside buildings/UFOs you can't get a decent lock on them due to the render engine forcing roofs to be drawn until a soldier is very close or inside the building/ufo.
What I would like to see is IF Aliens are spotted inside a building/UFO by your team then simply moving the cursor over top of that building/UFO tile removes the roof, because you can see inside anyway and why even bother allowing us to shoot at the Aliens inside if we can't see them on screen due to roof being on top!
I'm pretty sure this would be easy to implement, tie mouse cursor to trigger remove roof with a small script that checks if Aliens seen by player or not. Otherwise I will haft to look at hacking this game to do it myself because it is very frustrating getting shot by a spotted Alien and not being able to target him because scanning your mouse around reveals no target and your forced to put a soldier in the door just to remove the roof resulting in him being killed due to reaction fire!
Maybe this has been suggested before, why isn't this fixed/implemented already I do not know!