Well I see what I wrote for this post didn’t show up. I am very sorry about that.
Here is a repost.
This was parked outside of the grocery store when I came out. These box trucks are popular to build into a camper van for they have straight sides and ninety degree corners. Much easier to insulate and cover walls, install cabinets and counters plus you can stand up in them. People will remove the roll-up door in back and build a wall for a standard swing out door. And too people cut a walkway in the cab between the seats to enter the living area without having to do so from outside. This guy had these HUGE solar panels installed on the side. Why? Maybe the roof had a skylight roof like UPS trucks have. The panels were securely attached so it would be difficult to remove.
Most of these trucks are retired U-Haul trucks with the lettering removed before sale. This as you can see was not. He may have wanted to leave the lettering in place so he could “stealth camp” on city streets. Or maybe he just got the truck and took off leaving the cold of Montana and will fix it all up when he returns home.