One of the things that I have been working on is a folding bed for the back of my daughters 69 bay 8 seater. Because the backrest on the third row seat is only held in place by a couple of screws it was removed to allow just enough room to fit a folding board that will be long enough for someone under 170cm tall to be able to lie comfortably. Starting with a 2400x1200x12mm MDF sheet it was cut to make two 800 long sheets joined by piano hinge. I then trimmed the corners of the folding part to clear the roof lining whilst opening/closing. I'm going to fit a couple of slot-in legs to hold the board above the rear seat base and then all we need is a foam mattress that's cut to size and bobs your uncle! The folded board can then be pulled out when not needed.