The way I do it is to have dedicated cars: one for the spouse and another for me. I dedicate my Mazda3 to my commutes and I'm the sole driver. Otherwise, there's no way I would bother keeping up with my mileage.
My only "hypermiling" is to keep my speed moderate and do obvious things like coasting to a stop sign.
My wife does neither.
It is spousal harmony and long experience that prevents me from asking as a passenger in her car: "Why are you still accelerating when you can plainly see that stop sign looming 75 feet ahead?"
__________________
|