My brother was doing a search for 'dual cab tray size' and sent me a photo of my own car! I had to join just to see what it was part of.
I had this tray engineered to be legal length 1800x1800mm
Then had an extension made that would slip in the back. All I have to do is take the tail gate off, slide in the extension & 2 bolts underneath to lock the trays together. It has 2 x 2ft extension side gates that lock in and then the tail gate slides back in at the back of the extended tray. Wahlaaa