Mike and Molly -Select AV1, or AV2, or any other source that is not playing. This source will be silent and the only thing you will hear are the GPS prompts.
My DW, incidentally, found a way to display time on the screen. This is what she did.
1 - From the screen that has the maps
2 - Look at lower left and you'll see a small icon that resembles a compass
3 - Press it (BTW - I think what is really going on is you press in the lower left area that is bounded by white lines and that is displaying the three top to bottom parameters.)
4 - This takes you to the screen that has 7 or 8 parameters and that summarizes the trip. This screen has speed, miles left, current time, etc.
5 - She was driving, but I saw that she was pushing on these individual items, and in so doing she was able to select which three of these items would show up on the map screen. Note that you can also influence the order of these three icons back at the map screen from this screen. There is a bar with three tacked squares next to each item. As you push the item you will see that one of the three squares that make up the bar goes white. This is showing the relative position of each of these items back at the map screen.
6 - Once back at the map screen, in the lower left area, you see the three items you have selected for display.
7 - If you de-select the compass icon, it will not be there on the map screen, but whatever you selected to be in its place you can push to re-enter this view. Here again, what I notice is the region that is the three items and that is bounded by the white lines, in the lower left of the map screen, seems fair game to push on to get you to the screen that allows you to control the visibility of items in this corner of the map screen.