There was a Toyota employee in another thread, who mentioned, there will be zero changes: Toyota will leave the Prius Prime totally unchanged for the year 2018 other than TSBs+software bug fixes... I *really* hope I'm wrong!
No memory seats for the Prime (it is $10k cheaper than your loaded Sienna) but at least with the 7" unit, you can have custom radio presets (I'm sure there are other things saved) for each cellphone that's connected. It might carry over to the 11.6" unit that you have. It'll be on the main setting screens called "Driver"
I know for a fact that there is a September build run of 2017's, so it certainly won't be before that.
