I want one, but I'm probably going to wait and see if they make one specific to the CX-9 (though not likely). While the one they make and offer for the 6 will fit the CX-9 just fine, the CX-9's engine bay has a little more room behind the driver's side headlight. A CX-9-specific version would either have a longer tube or a longer filter.. or, dare I say it, another elbow that turns down behind the headlight and into the bumper, cold air style.
I'm quite sure both versions would function the same, since there's no airflow in the space behind the CX-9's bumper. I suppose one could modify or remove the black cover right above the foglight to create a bit of airflow, though.