Here's the outside:
And the inside:
It's got a gage for current MPG, and it tracks overall MPG as part of the trip meter. Right now I'm averaging 33.2 MPG, but I've only driven 60 miles so far. I talked to a guy I know who has one and he averages around 45 MPG.
I'm pretty happy with it. Now I need it to get dirty so I can stop worrying about it getting dirty.