Hi Steve,
great job you are doing on the i3 :-)
I would like to suggest to keep a feature using BMW's REST API optional in your module. Ideally as "OPT-IN" from the WebUI.
OVMS users like me use OVMS as a complete replacement for any "calling home" functionallities by the manufacturer. For privacy reasons I don't want to be forced to set up an account at the manufacturer. I think OVMS should best be useable without forcing the user to have to register with the manufacturer (and therefor will be tracked by the manufacturer). If a user decides to do so, no problem. But the module should be able to work without connection to the manufacturer, I believe.
Again, great job you are doing. My neighbor owns an i3. He is thinking about using OVMS now too :-)
Greetinx from Bavaria (50km away from Munich)