ZMAN : You can totally do that too & have a mini camper. I like the first idea, it's more efficient for traveling long distances & having your car normal too with dealing with traffic. The car is set up to be a camper when needed with outlets, climate control, and storage. Otherwise you need to idle a gas car, which isn't good for it.
@kyleven : I dont think you would have to idle a gas car, they make pretty compact all electric generators now, that you can charge with solar or plug into an inverter while you drive. I think thats what I would set up on my camper if I build one.