After messing around a bit with the mirrors and antennas, I was consistently in the 14-ish mpg mark. I tried removing the "cold air snorkle" but all I noticed was an increase in noise level and a decrease in throttle response. No changes in MPG, so I reinstalled it.
The one thing I did that I know improved fuel economy was the driver's side front fender flare. I hit my highest overall MPG when I had the flare finished, at 15.5mg. Unfortunately I don't have any decent photos of it, just this one from when I bought new front rims in December and had to redo it!
I had also started on a driver's side bellypan, you can see the front section with coroplast.