Live with it. I have same situation, the little dots bug me, but I live in SoCal, and dry freeways with sand and dirt flying around, a little sandblasting is inevitable. It's not worth chasing on a driver.
The only real solution is a repaint, and based on the environmental factors you mentioned, it will just do the same thing all over again.
Or you could plasti dip the whole thing. But if you go that route I think you are legally required to buy a big fart can muffler and bolt a big wing on the trunk...