Auto brightness on Nav Screen

I cant seem to get my automatic setting to work for adjusting the brightness of my nav screen.  Has anyone been able to make the auto tab work?  I am tired of switching from day to night whenever I get in the car.

I hear you.  The only way I have been able to adjust it other than using day/night mode is by decreasing the brightness of the guage displays when driving at night.  A pain in the ***

There is no way, annoying isn't it. The best way to do it is to have the NAV disc in and hit the voice recognition mode button. Say "Display, Night Mode" or "Day Mode" whichever you are trying to get.