Just thought I'd update here what I ended up doing to get CarPlay sorted (TLDR, it works)!
1.) Speak to Shawn!
2.) I bought an entrynav2 unit which I checked in advance was:
a.) not bricked
b.) had the purple w-lan port at the bottom left as you look at the back of the unit (2nd connector in). I got this from eBay for £170.
3.) Bought this cable from Amazon to connect a laptop to my car:
https://www.amazon.co.uk/gp/product/B07B2HZ64Y
3a.) Bought this w-lan aerial to plug into the new headunit:
https://www.amazon.co.uk/gp/product/B07YXPFGRC
4.) Fitted the new headunit in the car
5.) Via Shawn got someone to code my old FSC codes and VIN onto the replacement headunit
6.) After that was all done and tested as working
7.) Ordered the 143 FSC code via Shawn's contact that is specfic for my VIN, these come from BMW
8.) Shawn's contact remotely coded the CarPlay to my car via my laptop and the OBD cable.
9.) Connected my phone and got CarPlay
Thanks for the help all, and especially Shawn.