Wireless CarPlay & Android Auto for BMW NBT / EVO / iDrive 7 / 8

Recognise any of these?

You bought your BMW used and it has the NBT or EVO screen, but CarPlay was never activated — so your phone just sits in the cupholder while you squint at Google Maps on a tiny screen.
Your dealer quoted you several hundred dollars just to enable a feature that's already physically built into your car.
You plug your phone in with a USB cable every single time, and the cord gets in the way, snags, or you just forget it at home.
Your mate's newer BMW connects to CarPlay the moment he gets in — yours makes you dig out a cable every time.
You've tried the BMW Connected app workarounds and they don't hold, or your iDrive version isn't supported.
You're not sure if your specific iDrive version — NBT, EVO, iDrive 7, or iDrive 8 — can even be retrofitted, and no one gives you a straight answer.

BMW CarPlay activation EVO
With antenna 
With coding cable