My commute is pretty much all hwy with minimal stoplights, with the few I have, I'm usually able to judge when they'll switch so am able to adjust speed to avoid a complete stop.
Without doing any advanced hypermilling tricks, (pretty much referring to turning off the ignition on downhills), I'm averaging upper 40's. I haven't been able to hit 50 but if I could find straight gasoline without the 10% ethanol blend, pretty sure I would get it.
I try to keep the speed constant at 55 to 60 and only go higher in fifth gear on some descents where the car is accelerating only from gravity and not the right foot. I also use the AC but try to cut it off when climbing and try to avoid it as much as possible but late afternoon or early evening it gets just too hot right now.
Gas mileage with this car in stock form is incredible. I've thought about mods but fear they may actually deduct the phenomenal gas mileage.