It seems like there are two types of adjustments for the Nav screen. There is a day / night / auto mode that you can set in the menu. But there also seems to be some kind of auto dimming feature as well which in my LTZ seems overly sensitive and switches at the most inopportune times. I can't find any adjustment for this (other than the dial dimmer on the left side of the dashboard). I'd love to turn it off. Anyone else with this issue / solution?