Well, the house isn’t really trashed if you look closely. It’s very messy, embarrassingly so. Maybe they intended to go back and tidy up, maybe not. But it’s natural for Penny to try to blame it on someone else, real or not.
Someone *did* trash the car deliberately, it may have been people who didn’t have access to the house but it does look like it was done to spite Bonny, so definitely someone in with the tranchers on some level.
The “guests”, if any, could have been camping on the land, is what I’m getting at. But then J had his own trailer and could have just been up there seething after penny locked up and left.
Hope we find out.