Hi,
I would leave a little bit of the grill open, until it gets cold?
I had to fill the tank before my commute home, and I got 47.1 average (on the SGII), so the tape at the top of the windshield may have helped raise the FE by ~3mpg!
Here's my pictures (I added the narrow strip just below the wide one at the top of the windshield, and I have no idea if it will help or not):
The tape on the side window above the mirror was needed to keep the rubber gasket in place --after I put the strip on the A-pillar, the air coming around the corner started to pull the gasket out!
Closer shot of the wide strip at the top of the windshield. I added the narrow strip just before I took the photo, and I don't know how it will do yet.
This last shot has one piece pealed back to show the bump and groove in the stock set up.