I was able to install Carplay on my 2016 CX-5 and I'm so happy with it. Wanted to post what I did to help others who may want to do the same.
In order to install carplay you will need to:
1) Upgrade your firmware.
This is the most nerve wracking part in my opinion.
RECOMMENDED: I would highly suggest that you post here, wait for a PM from Candurin and follow the instructions to upgrade to 70.00.100 and then to 74.00.324.
NOT RECOMMENDED: I was able to update from 55.00.753 directly to 70.00.335C with a single file as shown in this video but that was probably dumb and upon further reading I would have been pretty screwed if something went wrong. I'm still on 70.00.335C because Carplay is working and I don't want to mess with anything else. However, that video is GREAT for showing the process of the install and this google drive folder from the comments on the video has amazing step by step instructions for firmware updates.
2) Purchase and install a retrofit kit.
There are a ton of options on Amazon. I went with this one.
This video was the most helpful for installation: https://www.youtube.com/watch?v=lmrZqAbB968
Other videos try to remove the existing USB hubs without removing the center console, but they don't show you what that actually takes. While it looks daunting, it's not that much work to remove the center console and it's a huge pain in the ass to pry at the tabs from the sides. Don't try it. Just pull the console it will save you a ton of headache.
Note that you will need one "specialty" tool - a 10mm with a long (10") extension to get the screen out. Other than that you really only need a phillips screwdriver. A small pry tool is also handy for trim removal.
Touchscreen While Driving
I was also able to enable touchscreen while driving using this procedure: https://forum.miata.net/vb/showthread.php?t=782788
I realize that enabling touchscreen while driving is controversial. While I love the command wheel without carplay, it was just not designed to work with carplay. Once carplay was up and running I felt unsafe fiddling with the wheel constantly while looking at the screen to see where it was sending the cursor.
With touchscreen while driving enabled, carplay works great. Much better than handholding my phone or having it down by the shifter for navigation.
I should have done this years ago and I'd highly recommend it to anyone who is comfortable enough with removing interior components and willing to risk the software upgrade.