[Flakbadger]

Well my friend, I do next to no EOC (Maybe once per tank, just for ****s and giggles), lots and lots of coasting, and only drive as slow as I think I can without inconveniencing other drivers, and I don't think I can do very much better.
I would love to buy an Ultraguage but I lack the income to drop 60 bucks on something so frivolous, and don't know that I could really get much above what I'm getting now.
As far as aero goes, it depends on what you want. I have been itching to make a grille block and rear wheel well covers, but I am unwilling to have something that looks slapdash in execution... So I haven't done anything yet for lack of time to make it look "good."
I am not disappointed with my results with those restrictions. As others have mentioned it depends on your car.