After having absolutely no luck or solutions as to why my GPS would not switch over in the "automatic position" from day to night, I took my 2012 Prius 3 up to the dealer today. After checking it for about 45 minutes, they told me there was probably a loose wire up inside the dashboard and I could either leave the car there or come back later as the dashboard was going to have to come out. I left with the car, ran some errands and returned the car a couple of hours later. I received a call from the dealership about an hour later that the car was fixed and they did not have to remove the dashboard. It seems that there are two settings for the automatic day/night setting--one is on the GPS, but the other is on the display, and that will override the GPS setting. Sure enough, when I got there, I turned the lights on, and the GPS went to the night time setting automatically. I asked for them to show me what they did. Unfortunately, the mechanic was out to lunch, and one person was able to get into the "display" screen which showed a "daytime setting." He was never able to get back into it. I decided to wait for the mechanic to return from lunch. He turned the lights on, went to "display" and could not get the "daytime setting" to appear. We then went outside and tried it, and still no luck. Pulled the car into the shop, and bingo, the daytime setting was there. So, if you are having trouble going to the automatic setting on your GPS, make sure that it is dark enough, or put something over the sensor on the dashboard. Go to the "display screen", have the lights either in the park position or the on position and you will see a small menu in the center of the screen which says "daylight mode"...IF THERE IS A SMALL orange mark next to the writing, this means it is in fact, in the daylight mode, and your GPS will not operate automatically from the GPS from day to night. PUSH the "daylight mode" screen and the orange mark will disappear and you will notice that everything darkens substantially. Go back to your contrast/brightness controls and adjust accordingly for the night time setting, and that should do it. Unfortunately, my daytime setting was set to daytime from the factory, and l'm sure that was a mistake. I read nothing in the manual about this--maybe it is there, but I have never seen it. This is a new GPS on the Prius 3's for 2012 and I think the Prius 4's have the same GPS. The Prius 5 uses a bigger screen and probably different menus. By the way, the "indent" on the dash lights thumbwheel will override the night time setting, and put you back into daylight mode. I hope this may help someone else if they ever encounter this problem.