It's too late now, but I would have put the metal stowage box on the rear deck, not on the side. It's more likely they'd weld a box to that panel. Now it's there, I'd suggest a horizontal retaining strip between the 2 brackets.
Good work on the soft stowage. I'd suggest another layer piled up towards the rear.
Did you have trouble cleaning up the appliqué armour panels on the sides? As they are moulded on, the sides of the panels aren't vertical, and fixing that is a pain.