I've not had a problem with it being too hot in the back. True the flow thru the B pillar vents isn't particularly strong, but there are also vents under the front seats, and the centre console vents can be directed down the middle. I don't have the pano roof though (can't see the sense in having that in Australia!) and I do have the LR window blinds in the back which I thoroughly recommend to keep direct sunlight out. There is also a "max aircon" button on the climate control system which is good at cooling the car down when you first get in on a hot day.
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