Was researching for awhile to see what options us BIS01 headunit owners had to retrofit CarPlay and it seemed like the one offered by SCP Automotive (https://scpautomotive.co.uk/products/mini-f56-bis01-carplay-android-auto-module) might be the cheapest option for those of us based in the USA.
I found another seller for the *identical* board here for a almost a 1/4 of the price: https://isudar.com/products/for-bmw-bis-system-6-5inch-screen-carplay-android-auto-adapter?variant=41209663782994
At first I was a bit suspicious, but I found out Volvo owners on Reddit have used this company extensively coupled with at least one other review from the mini56 forums.
Communication was good, they answered questions about tariffs (they have a duty paid option for ~$20 more that I used), shipping to California took maybe a week, and they reached out to confirm compatibility first.
The provided installation instructions aren't the best, but luckily you can just follow this video guide here: https://youtu.be/L8mA5AHHd48?si=JRHf1wARXHwg_Bv-
It took me a couple of hours to install because the FAKRA connectors literally would not budge and I didn't want to yank on the cables (around 1:24 in the linked video). Spent the better part of an hour just on this. If you're not savvy in installing electronics (like me), budget a lot of time for the whole process.
Overall the product works great: Bluetooth audio works seamlessly, when reversing or parking it switches to the rear view camera, can use microphone mode for voice commands in Google maps, etc.
One note is that it would randomly disconnect the unit on occasion, after a while I realized that it was related to engine start stop - now I just stay in Mid mode and disable it - no more connection issues.