The trays were slightly over sized so I had to trim some material from the centre ends of each to get them to fit together against the bulkhead. Slightly daunting as you wonder if you are actually doing the right thing !
There are no pre drilled holes or a guide ; I found one on the Samba forum.
The plastic is fairly thick, and looks similar to the black dash in my ‘70 Westy. Time will tell how durable they are.