Prius owner here too. Prefer the bike over the Prius any day. The wife does use the Prius plenty, though. We do have another "car", a Ford Ranger which is driven a few hundred miles a year. Too bad we don't have ZipCar or the like here, because that would work very well for me. For now, I'd be pretty happy with the justice that Pay-As-You-Drive auto insurance would be.
If I "needed" another car today I'd be looking for a reliable used car, and save big bucks vs. buying new.