here what I've found out:
Mine is a 530d Model 2013 (manufactured 10/30/2012) with 2-Zone climate.
- the manual describes only the features (front and rear vents) which come with the 4-Zone.
- means for the 2-zone there is only one wheel in the dash with red/blue marking
- and this only works for the front vents
- the rear vents (no red/blue wheels, only open/close regulation) when open always blow at the temperature the AC is set to even if the wheel on the dash is set to blue (cold).
I've tested this with A/C set to AUTO, Temp to 22° C (ca. 72° F) @ outside 5° C (41° F)
and it works like this no matter if the button ALL is pressed or not.
hope this helps a bit.....