But then you gotta keep adjusting it everytime someone pulls up behind you at a different distance. Easier to have an autodimmer on them too.

As I said, if you position your mirrors so that you don't see the side of your car, what you end up with are side mirrors that only show you what's next to you, and behind you in the other lanes. You don't need to see your own car in the side mirrors. In the dark, what you end up with are side mirrors that don't have the reflections of the cars behind you, they only show up when they are in the lanes on either side of you and are close enough to worry about.