Well, the boattails been done for over a week now, guess it's time to get some pics posted up of the finished product.
It's pretty amazing how much the boattail has helped with coastdown times. I'll look down at the speedo after a good 10-15 seconds of coasting on level ground and I *might* have dropped 5mph (from 65 to 60) on a bad day.
Mileage seems to have been improved at least 10%. I'm now able to consistently hit 55mpg burning 87 octane E10 gasoline. I'm positive that I'd be reliably in the 75mpg range with "real" gasoline.
I scavenged the key mechanism out of the hatches "tailgate" and with a little copious modification it made a serviceable lock for the new rear window.