PA Outback

After seeing The Lost World, I knew that the Subaru Outback was the perfect vehicle for after the world ends. If it can handle dinosaurs, it can handle anything. On top is a tent with solar panels attached, because I reckon that if you're looking to avoid raiders and marauders, then you're going to want to sleep during the day and travel at night. Also, the tent being on top will prevent most critters from being able to reach.

EDIT: It has recently come to my attention that it was a Mercedes and not a Subaru. My bad