That's why there will be a good audio system in the car. Also, said passenger could bring along a laptop and a selection of movies, or games, etc.Also, I'm not sure how comfortable a passenger will be in the back, looking at the read of the driver's seat for hours on end.
I imagine the Elio can pull one of those small "teadrop" campers. Even if you don't use it for sleeping, there's more than enough space in there to carry extra suitcases, etc.