I recently bought a 2003 STS with all the bells and whistles. After carefully reading the Owner's Manual, I'm beginning to feel somewhat comfortable with most of the seemingless endless list of features. One thing is really puzzling me however. Based on the description in the Owner's Manual it's my understanding that the rearview mirror should display compass headings, and these headings should be visible in the mirror when the ON/OFF switch to the left of the OnStar button is in the ON position. When I toggle the ON/OFF switch, little green lights come on at both ends of the controls section of the mirror, but no compass readings are displayed. Is this a problem, or am I just missing something?