I just bought the same car and added the box (I have the larger screen stock). Carplay works well as doea the stock camera. You can switch between the MMI and stock infotainment by long pressing the menu button.
Weird of advice, if you're going to code The car with Bimmercode, do it before you install the MMI.
This is the box I bought: Road Top Wireless Carplay Retrofit Kit Decoder for BMW NBT system 3 4 5 6 7 Series X1 X3 X4 X5 X6 2012-2016, Support iOS 13 14, Android Auto, AirPlay, Mirroring, Rear View, USB Drive, Firmware Upgrade https://smile.amazon.com/dp/B084M1M4P9/ref=cm_sw_r_cp_api_i_N27H6BRD64AJQWA9WSMY?_encoding=UTF8&psc=1
https://www.amazon.com/dp/B084M1M4P9?ref=ppx_pop_mob_ap_share This is the module she got.
Update: Just ordered and installed one from “Road Top” on amazon. I’ll link the product for whoever is interested. Install was very easy and didn’t even require the external mic or aux input for my f30.