Looking at 2007 Toyota highlander

Going next Tues to check it. I know how to inspect mechanicals, engine (my 2004 Avalon has the same 6-cyl power plant). This vehicle has a trailer hitch: I will ask what was towed and how heavy. What else should I ask about /look at related to towing?
I love the Avalon as road car but can't fit much into it. I intend to use the larger SUV as a stealth camper.
Another aging motorhead.