Add an audio alert for entering a fogged or ion storm sector, or at least ion storm sectors. Set it up so that it can be adjusted from 0 or off to full volume similar to the damage screen flash.

I think this would add a bit to immersion by adding a sense of danger and alarm to the players interaction with the environment.

I'm sure this could and possibly already has been done via plugin, however I think it should be a default part of the game.