As Daox said, check out the 65+ efficiency mods. You are bound to find a few in there that would be easy to do. The
ScanGauge is a biggy, but you got that.
I noticed you posted your milage in Liters/Km. Aside from it being in metric, is it a Canadian thing to do Liters/Km versus Km/Liter (how we here in the states for Miles/Gallon)?