Don't have an answer to your particular situation, but if it helps: most manufacturers try to keep the manufacturing process simple and cost effective. Under the skin, most models are built the same, with the same wiring looms and electronics. The difference comes at the end of the line when they install the options particular to your model. Chances are, you CX-9 already has the necessary systems installed for your particular need. All you may have to do is find the right seat and stuff, and just plug it all in.
Example: my 2002 Nissan Pathfinder was a lower level model, with manual cloth seats, no fog lights, no overhead console and plain black trim. I went to a junkyard and found a top trim junked Pathfinder with heated leather electric seats, fog lights, wood trim accents, an overhead console and other stuff. The wiring was all there for that stuff in the vehicle. All I had to do was plug it all in, and add a few switches (also from the junker). Every thing worked. Hopefully Mazda does the same.