I have a brand new westy style cab bunk that came with the 4 half moon type brackets for fitting. The slot the bunk fits into is wider at one end. I had two original ones fitted to the van (left by PO). These were fitted with the wider part of the slot at the bottom, but this seems to encourage the bar to slide out. I would have thought the narrow bit goes at the bottom, so the bar is more snugly located. Anyone know which way up is right? The instructions are a bit vague and I don't fancy using the 21 month old to test which way is better!!