Driving at night is the best. Especially on twisty mountain roads. During the day, you have very little warning that there are oncoming cars. At night, their headlights give much more advance notice. Unfortunately, deer are not equipped with headlights and you have to really watch for them.
I usually do not allow cars to remain directly behind me very long. The mirror is not a problem.
Looking forward to our November Rally to Laughlin. Fourteen hours of driving, probably half at night. See:
http://carzero.freeservers.com/itn3-fly.htm
Paul