I discussed this on another forum with a guy that apparently does EV conversions for a living. While there is a pretty significant weight difference between the Metro and the E15 Sentra, the difference in CDA is negligible. Also, I'm sure a good portion of the weight difference is the size of the engine since we're comparing a 1.0L to a 1.8L.
I've Ordered an Ultragauge, and I've begun a bit of hypermiling. I have no doubt I can get to 40MPG, but I won't be satisfied till I'm in excess of 60MPG, which undoubtedly will require some aeromodding. My first step will be installing an engine kill switch. Next will be disabling power steering and maybe even yanking out the compressor and other A/C giblets. I owned a car for 5yrs that came from the factory w/o A/C, so I doubt I'll miss it.
I'll eventually follow some of
blownb310's techniques in aeromodding, although I'll probably improve on the kammback.