Believe it or not, I think if you were to come ride my route, you would feel more comfortable with a mirror. I can't match you in traffic volume but I can beat you riding with 26 wheeled double trailered trucks that can come up on you in both directions at considerable speeds. This is a road without a shoulder.

I don't question you riding without a mirror at all. In your situation I may not either. One thing I know for sure though is that I wouldn't listen to music if I couldn't see these trucks coming.