A bit of tinkering with Menyoo and the Brute Stockade belonging to Gruppe 6 becomes a modest motorhome.

Known bugs/issues:

You cannot watch the TV, toke the bong or even enter the rear space full stop.

Installation:

1: Install Menyoo by MAFINS:
https://www.gta5-mods.com/scripts/menyoo-pc-sp

2: Extract "Stockade Camper.xml" to "E:\SteamLibrary\steamapps\common\Grand Theft Auto V\menyooStuff\Vehicle"

Happy camping!!