Car seats in motorhome?

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My IL's were talking about getting a motorhome to replace their travel trailer today and I mentioned how I thought car seats weren't ok to be installed in them and they all jumped on me that it wasn't true. They went to some motorhome show and they now have seat belts yada yada yada. I tried to explain how the seat belts might only be bolted to wood, or that the car seats could not be installed on a sideways seat and I was told matter of factly that the seatbelts are bolted to the frame, although I swear in the middle of the cacophony one of them said they also have 5 pt harnesses (wtf?) in them. Sooo I was wondering if anyone could shed some light on the subject for me because I've googled til my eyes are bleeding and I can't really find anything other than "multiple seatbelt locations" but nothing specific as to what kind or where or what it's bolted to. TIA!