https://aos.bmwgroup.com/web/oss/start - you’ll need something like an “icom next” to connect the car but it’ll do e-sys with the ability to install the latest firmwares.
Some stuff (quite limited though) is available through the car data api - i think most f-series and all g-series i think have telematics. I have a 2018 f15 and that works.
https://bmw-cardata.bmwgroup.com/thirdparty/public/repair-an...