You are talking about the "Audio Pilot" thing. Mine just has on or off. I didn't see any other adjustment, but they like to hide stuff.
Yes. I looked in the manual again and under Auto Pilot it says it has a low, medium or high setting (for the amout of compensation desired) but mine too is on or off only. If I turn it on it over compensates for noise and turns up the volume to high. If I then turn the radio down it is too low when stopped. If I knew where the microphone was that picks up the noise I would experiment with covering it with tape or foam. I would really like this feature but can't use it as it is now.
BTW when you were adjusting the navigation screen from the menue were you changing the contrast which is the bar on the right side (on mine) with the brightness bar being on the left. The contrast setting will change the brightness some but does not allow a different setting for day, night or auto.