Technic - in which menu did you find automatic day/night switching? I've spent a considerable time searching through the various IDrive menus and have never come across that option (my car is an early 2009 build with IDrive software that was last updated in Nov 2008). Could it be a function that was added in the latest IDrive software update?
2014 Z4 35is Deep Sea Blue
2009 E92 335i X-Drive 6MT - Sold