There isn't a van DIY thread so thought I'd post here. I've just bought a van for touring with my band and to make some $$$ driving other people's bands. At the moment there is one small bunk but it'd be handy to be able to sleep at least a couple more people in relative comfort if need be. I was thinking just a sheet of some sort of wood stuff (I think that's the technical term) to lie between the two rows of back seats, which face each other, spanning the foot well, to create a flat space about the width of a (very short) double bed. My question is, what materials should I be looking at? Must be able to support a human's body weight and be light enough for one person to lift and ideally be super cheap. Also, reccomendations for some sort of cheap foam to use a makeshift mattress would be appreciated!