Have you considered a 2016 Buick Envision Premium II? I mean, sure, it's a CUV, and sure, it has an automatic...but it will get 32MPG on the highway, which is better than any EV, and don't forget the three-zone climate control in case you and your wife get into a fight - being in different climate[-controlled zones]s means you can't hear each other. No more punches to your arm.
Perfect solution.
Move aside, MIATA, 2016 Buick Envision Premium II is the new answer!!!!!
In all seriousness, the Volt is a fantastic car. If she's content to give up the MT for fuel economy gains, you can't do better than that.
"BUY ME!"
...but, ooooh, shiny!