pmekdahl01 said:MAGIC!.... I don't know yet, still dont have a mattress. Maybe some Velcro strips.
My van has body pillows that make up the seat/back. The back part is held to the wall with velcro. To make a bed, take the cushions off the wall and assemble the bed. It works okay but velcro of course wears out and doesn't stay in place with shifting body weight when sitting.
I've often thought that a better solution would be to have one larger cushion (such as maybe a futon mattress), and sew some heavy loopholes into the mattress, and put some low profile hooks on the wall to hang the loopholes from. That way even when sitting and slouching the mattress can't come down the wall and slide off your seat. When you want it to be a bed, just pick it up off the hooks and slide it down.
That's the idea I had that I plan to implement one day, anyway. Might work for you.