[brucepick]

Mazda 5 sounds like a good idea.
Subaru has the 4wd system.
Of course that's nice for traction but it's bad for FE. More drivetrain mechanics going on, always. All those whirling gears add mechanical complexity and drag to the system.

A block heater sounds good too.
Plenty good comments on those on CleanMPG.com.
During the first few minutes after a cold start, a lot of energy goes into heating up the block. If you start out with a warm block you're way ahead of the game, as long as you have a good AC source and can set up a timer to run the heater for maybe 2-3 hours before you want to drive. The freeze-plug type heater is the way to go, is what I hear.

The cost of electricity to warm it is definitely less than the cost of the fuel that would do the same warming job. That math has been done several times.