I fully understand about the daughter, I bought mine almost 3 years ago to the day right after my daughter had turned 4, my wife and I wanted her to ride with us so I had a roll cage built over the cargo box and put a small vinyl roof on the top of it that was held on with velcro, then I insulated the bottom of the box, cut out the square plate on the factory cage so she had an unobstructed view forward, and lastly I secured a child's car seat in the box. I can't tell you the countless hours she spent in that chair riding on trails or small dirt roads in the mountains, the chair wrapped around her head on either side keeping it from being flung back and forth, I also can't tell you how many hours she spent sleeping in that chair as we jostled down those back roads, across streams and river bottoms, the motion, and noise lulled her to sleep. She out grew it a year ago and I have thought about mounting a small UTV seat sideways in the box but I wonder if the motion would be uncomfortable sitting that way, but learning about bump seats a week ago on this forum I am now thinking of using the bump seat concept but slightly modified, I would mount the seat in the box with only her legs inside the cab between me and my wife, when she outgrows that I will be in trouble because then she'll be wanting my seat....now I need to think about where else I can mount the prefilter I have on order, or maybe I just mount the seat higher than I was thinking above the prefilter, which would solve the rain issue for me.

I think you can do the third seat in the middle. You should start a topic on this. Some of the guys might have some good ideas.