I also just picked up a 2013. Give Toyota support a call. There is a free downloadable software update. You will need an 8GB (no larger) USB 2.0 USB stick. Instructions are contained in the download they will send you.
I just updated the entune software in my 2013 Prius four to version 5.2.0. if fixed my issue with the USB freezing and so far so good. it was a simple download onto a USB drive and took less than 5 minutes to install. Updated from version 2.?? to 5.2.0. Do a search for entune update and you'll find it. I'd also like to know how to get updated maps for the Nav.
The map update is via a download requiring a unique download key. My dealer said it costs $169. Even he thought this was ridiculous. Posted via the PriusChat mobile app.
Are you posting about a 2010? 2010 and -11 with the 7" nav and CD changer have a simple nav DVD. When you open the cover to load CDs, you'll see a separate slot for the map dvd below. You can find out what version you have from the INFO / map data screen. The screen also has an eject button to pop out the disk. You get a newer disk from the dealer and pop it in. Done. The 2015 one is 86271-GEN06-15 (edit: that's the one covering US/Canada), but -16 should be out in a few months if you want to wait. The 2012 facelift brought two different nav options, the 6.1" or 7". The 7" looks much like the 2010 but has an internal hard drive instead of a DVD. It can be updated by buying a serial-numbered DVD, getting a license key that depends on the DVD serial number and a unique number displayed by your nav unit, then popping the DVD into the regular disk slot and entering the license key. (If you prefer, you can copy the DVD contents onto a USB drive and plug that in, as long as it came from the same serial-numbered DVD you got the key for.) Haven't looked into how the 6.1" is updated. -Chap