Yes I made one works brill, first made a stainless dog guard, on my seat there were two holes on top, one left one right, got an old head rest, cut the legs off, these welded to dog guard hey presto seat comes over, dog guard becomes bed end, made 2 straps attached to dog guard, with big washers these attach to old set belt holes unf bolts by the way, there is a hole behind the other column trim, run your thumb down it you will feel the depression this set up will stop the seat back from going down whilst climbing into ones pit.
Initially made three 9mm mdf boxes with lift off lids, but decided if I need to get to the engine, they would have to be removed possibly full of stuff, so made something similar to the guy on YouTube, made it out of 2mm ali checker plate, luckily I was able to get it made by a fabrication company I deal with, so it was folded and welded, basically looking fro m the top towards the front of the van, a large upside U shape with a box about the size of your engine lid in the middle with an upright down the middle for strength, this gives you 2 large suitcase sized compartments and three long thin storage areas about 8 inches wide, the centre is hinged at the top with a simple bolt through centre box into side boxes, glued and screwed some off cuts of 9mm ply 10 mm below the rims of all boxes, cut some more 9mm ply for the lids simple 25mm finger hole for removal of lids, result excellent lightweight storage box/bed very strong with access to the engine.
Bought a 100mm self inflating double mattress from decathlon, big but extreme comfort, takes some folding back but well worth the effort and the money (£79.00) I have the double seats facing backwards and can sit on them with the bed in place, in hind sight dog guard could have been 4inch shorter, 9mm ply will be getting changed to mdf (ply tends to bend and warp a little) this I will eventually glue some carpet tiles to, I will take some pics asap if anyone is interested, the van is in the body shop at present getting a new winter coat.
If anyone wants the old MDF boxes they can have but you will have to get them picked up em never used em
Steve