Confession time: I never expected to see an SUV owner obsess over FE. I wish everybody was like you !

One accepted approach you might consider is to give the feh to your SO, and start afresh with a new car

R2-E2, 2G Prius.
Highway/City/Husband/Wife MPG: 56.5, as of 12/2005, 26K miles

Jac Nasser, Ford President: "We are planning to launch a hybrid version of
this car [P2000] within this year [1998]. We will also make FCEV available in
2004."