I have something much simpler and ad hoc, but it's comfy and quick, a pared down version of my '70s Dodge camping van of yore, featured in my signature. Bottom layer is thin spring mattress glommed from a hide-a-bed, and on top of that is a futon. Neither one alone was cushy enough for my old bones, but together it's the Goldilocks zone. Perfect for overnight trips, short camping or just nap heaven when you're on the road. Fits two; that is, when the dog isn't usurping it.