Nav too bright at night

[kglesq]

I picked up my 2005 X5 4.4i today, and it is absolutely fantastic.

My one complaint thus far is that the nav screen does not seem to dim at all at night. On my other 2 cars (and every other nav screen I've ever seen) the screen is dimmer at night and changes to a different color scheme to preserve night vision, however in my X5, it remains bright and retains the daylight color scheme. This is pretty blinding, and I can use the brightness setting to turn it down, but then its too dim during the day.

Is it supposed to be changing to a night mode when the lights come on or is this normal operation?