rear AC control and the iDrive..
 

I'm curious, am I doing something wrong, or is my vehicle in need of a software patch, cause when I checkbox the box that matches the rear AC to the front it stays that way only until I power down the vehicle. When I go to drive it again after a few hours of power off It's back to separate rear control.. Is that how it's supposed to be?

The book isn't clear on this from what I can see.

Mine stays until someone in the back seat adjusts the temp.

I think it is simply used so the driver can either turn off the rear air or adjust it to the same setting as front on on one time basis. It does not stick.

Sounds like a single activation just like the auto venting system.

If the kids are messing with the temp control... you can force it during that ride. But on the next trip... any new passengers can change it.