How are each of these configured? What I am
most interested in knowing is, do
both options at least have vents for airflow in the third row? Thank you!

 

First row can be controlled from the front.
The the second row can be controlled from the front console, or the second row controls. If you have the package that adds the rear mbux tablet, then you can control it from there also.
If you have the rear mbux tablet, let it can be used to control the third row also in addition to the panel at the first row. There are no physical controls located in the third row other than to turn the heated seats on if you have that option.

As for the vents, the upper vents in both the second and third row is controlled by the 3rd row cooling setting.so if you set the controls in the second row 2 maximum heating, and the controls on the third row to maximum cooling, then the second row end up with heat coming from the lower vents or the side vent depending on the air flow setting wow the vents from the roof will blow cold air. Setting the third row to maximum heating what cause heat to come from electric heaters located underneath the third row seats.

 

You only get vents in the 3rd row if you order the 5 zone option.

 

Those vents on the roof/headliner isn't there without the 5 zone option?

Makes sense! Thanks for the info.

 

this is crazy, even with the 4 zone pkg you don’t get vents back there??

 

Yes. Need 5 zone for ceiling vents for 2nd and 3rd rows - otherwise occupants will fry in rear in summer. Main reason I bought the gls450 since my 2018 Q7 has no vents in rear..

 

Pathetic you have to select two a/c options to get the ceiling vents. Both Telluride and Palisade have them as a standard feature.

 

MB is not alone in this. BMW is same way with the X7. You only get 3rd row vents if you order the cold weather package.