Something that struck me is the reduced frequency of fill ups - even for my 400-500mi/week use. This gives me a little more leeway to be on the look out for cheaper gas (on the road, using gasbuddy on line etc.).

Since gas prices can fluctuate 10 cents or more within a few days, it might be cool to have the NAV system advise you when it thinks local prices/stations are offering relatively inexpensive fuel. Maybe it sees prices down by say 10 cents or more versus the last 1-2 week average...