Custom rear speaker enclosure

[360ian]

Hi everyone, I am thinking of adding some rear speakers to my 2021 T6.1. I have run the wires in and down the a pillar and tucked them inside the back of the glovebox at the moment. I was thinking of building a box that sits just inside the tailgate and runs the full width of the van and screws into the Pop Top bed board that I've just had installed.

Has anyone done this that can share any photos of the enclosure for me please!?

TIA