I was wondering if anyone could help on a the best way to approach walling my truck off I have 2 18" zcons facing forward and the port forward and I want to wall it off I was thinking getting cardboard and getting the outline of the rest of the space that I need sealed off and putting it on some mdf and cutting it out but I can't think of how I would attach that piece to my box without wood gluing it so if anyone could help ibwould appreciate it

I like the cardboard idea. Just know, a wall takes a lot of freaking work, time, and money. It's an huge task. The end result can be very pleasing if you take your time and do it right. My advice, is do, step by step, from the ground up. It is best to do it once the vechile is emptied. What I mean is, don't build a box, and slap it inside the truck. Make sure you do all the simple things. Run your wires, carefully and neatly, reinforce the panels of your vehicle. Anticipate things to start breaking lol and test everything before final assempbly

Well I already have the box built and want to seal off everything around it now