Checked out the system on a 2012 Prius III the other day, noticed two things of interest: 1) they seem to have fixed the issue where scrolling through a playlist would automatically activate the song at the top of the screen. Now, you can scroll to your hearts content and it won't change songs until you ask it to. 2) I was finding the nav display to be dim and hard to read, especially in the sun. Eventually I discovered that the problem was my polarized sunglasses; the display really suffers quite a bit when viewed through polarized lenses. This is very disappointing to me; I certainly do not have this problem on my 2006. Don't know if the 2010-2011 suffer from this or not. I would probably have to get new sunglass clips for this car, which is not a big deal but annoying. The operation of the system through the touchscreen seemed confusing to me, but I didn't have enough time with it to really judge. Thought you all might be interested....
The left half of the display has the same polarization issue for the main indicators on the 2011. The two sides are quite different: right hand side is direct display. Left side is mirrored. I suspect the reflection is what makes polarized viewing dimmer.
I have polarizing issues on my 2011 as well. I am not in the car right now but as I recollect, I have the same issue looking at my iPhone 4's display with sun glasses on as well.
I don't have nearly as much problem with my iPhone as I was seeing with the Prius display. I'll have to look at a 2011 and see how it compares. Yes, if I didn't use clips. Wonderful, won't-ever-be-without-them-again, magnetic clips that are easy to put on (and take off) with one hand in the car. do not know if they're available in non-polarized, I need to check into that.