First: I realize there has been a lot of discussion of the reasons for closing, and I haven't followed most of it, so I apologize for any redundancy here.
That having been said: Here is an example of a question that I think everyone will agree should be closed, and to which none of the close reasons seems to apply. It's not a duplicate. It's not out of the mainstream (except insofar as it's "out of the mainstream" to post without giving a minute's thought to what you're asking.) It's not engineering. It doesn't belong on another site in the StackExchange network (or anywhere else for that matter). It's perfectly clear, it's not too broad, and it's not primarily opinion-based. (And even if were unclear, I wouldn't want to choose that option, because it entails inviting the OP to clarify the question and come back, which is not an invitation I wish to offer.)
The closest fit I can find is that this is a homework-like question that shows no effort. But that doesn't really seem to fit either.
It seems to me that a substantial fraction of the questions I vote to close are uncategorizable in pretty much the same way that this one is.
So my immediate question is:
What reason should I check when voting to close a question like this?
My longer-term question is:
Would it make sense to offer "This question appears to be off-topic" as a reason for closing, without forcing the voter to choose from a submenu of choices that don't really fit? (I realize that one can enter a custom reason, but really, "this question appears to be off-topic" is all I want to say.)
Again, I suspect, but do not know, that my second question has already been discussed to death. But what is the answer to the first question?
Edited to add: It appears that the example I chose is not quite as egregious as I'd thought it was --- the OP seems to be envisioning a mirror mounted on the car, whereas I thought he was envisioning a mirror mounted on the road. So this is an imperfect example, but the phenomenon does occur, and often.