After a lot of angst waiting for the Miracast Streaming update to finally post under my VIN, I was able to download and install the update today in my 2017 Touring L+ with the theater package. The other thread about uconnect updates has great advice on what is needed to get the update installed, so I won't go into those details. What I want to highlight is that Streaming appears to only work with the built-in 3G hotspot in the 2017, which is just too slow and too expensive! Unless I am completely missing it, there is no option to select a wifi network other than that hotspot. I had intended to use the ZTE Mobley that currently provides LTE speeds for the chromecast and all the devices that the family uses in the van, No dice! If anyone has figured out how to use an external hotspot, I would love to hear how you got it done.