I gave up hoping that Tesla will bring CarPlay to my M3, so I went the DIY route and added CarPlay myself. While this isn’t as good as having the CarPlay interface on my main Tesla screen, I now have a CarPlay display on a cheap android tablet mounted to the left of my steering wheel. There’s a fairly inexpensive product out of China called Carlinkit (I got mine from Amazon, but you can also find it on Alibaba and eBay) that connects to the tablet via a USB OTG cable and to my phone via a regular lightning cable. This makes the tablet look like a CarPlay headunit to the phone and the tablet displays the CarPlay screen. The tablet connects to the audio system via Bluetooth and even the left track wheel on the steering wheel can be used to control the play/pause/next/previous media tracks in CarPlay.
Of course, this was after some trial and error. Turns out some Fire tablets have polarized screens that make them unreadable in landscape with sunglasses on and none of the Fire tablets I have seem to support USB OTG Y-cables that charge at the same time, so I ended up buying a knock-off android tablet can do OTG and charging simultaneously.
Also, this product also says it supports Android Auto, but I haven’t tried that.