I bought a Prius C navigation module on ebay and it works great PT296-47120. Updated ENTUNE also no issues
https://securedp.toyota.com/download...oyotaHeadUnits. As far as I can tell all the series entune navs PT296-47120, PT296-47130, and PT296-47140 work they are just different years I guess. Waiting on the GPS antenna to finish the install. I actually bought two of the modules by mistake, I am going to put one back on ebay I guess.
NOTE: I did have to do the diagnostic set up on the head unit to get it to recognize the nav unit. You hold down the audio button and turn the headlights on and off 3 times, turn off the car then turn it back on and it works. I did go through all the options in the diagnostic not sure if you have to, to get it to work.