The digital compass mirror in the e90 blinks a pixel check for about 1/2 second when you start the car. I just noticed that this morning. The display is obviously designed to do much more than just compass work. It appears that it could be time, temp, and compass, although I wonder where it is few direction info from, or if it's self contained.
If self contained, it
may be possible that the homelinnk buttons could potentially control the other options. (huge assumption, I know)...
Anybody have more info on the mirror hidden displays?
