Maybe an attempt at adding a third row seat?
I see six random spaced holes but no hole on the right is located on any single flat surface when the whole shebang could have been shifted slightly to the left. There may be a good reason for that but I bet there isn't.
I'm not trying to scare you but I'd be more worried about what other trailer park customization has been done regarding regular maintenance, so I suggest changing every fluid if you haven't done that already.