So My 2016 Model X is in for warranty repair to the HVAC box. The baffle actuators were making a very quiet grinding noise and replacement was needed. It's taking a bit longer than expected because the new part replacement apparently didn't have the pass through cutout for the ionizer, so they used the old enclosure. I remember there being a toggle option in the older Model S for the ionizer, but never had it in my Model X. I looked it up on the online parts database and sure enough, there's an ionizer. I ran across some older threads about the ionizer in the Model S and the absence of turning it on in the center stack. I guess they removed the button and it keeps the last known setting, unless you request it toggled remotely by service. Since I never had the setting, I wonder if it's on or off. Also, since the new part didn't have the cutout, I wonder if new models don't include the part.