Yup, that. I need to get one for the M135i as my old ELM327 1.5 adapter doesn't seem to like talking to the F20 like it did the E46. Although it might just be the dongle is fucked
I might as well get one of the fancier MHD/Carly/Bimmercode ones that'll do the ENET or whatever it is the F20 needs (I've not looked into it properly yet) so that if I do want to look into coding something in - say, electrically adjusted memory seats so I can get the auto-mirror dip functionality, or if I'm feeling more bonkers, the front facing camera to read speed signs

I can do it.
The old MSCAN adapter I had on the mondeo could infer individual cylinder temps and tell me the fuel pressure readings etc in real time, read the ABS module and other 'body control' type modules, so if it saves you *one* £80 diag visit (two months from now etc) because, say, the electric windows won't work one day, then it's paid for itself already, effectively.