BMW called my home number...so, maybe they did try to get ahold of you. Regardless, it should be no issue to have them replace it once you're back in HI.
From what I've found, while actually changing it doesn't take all that long (maybe half a day billed labor - probably shorter once they've done some), since BMW forces software updates from Germany, depending on their data connection and if there are any glitches, it may take a day to get all of the latest software installed afterwards. Some things are available at the dealers, but at least from my experience, on the i3, it comes from Germany and is customized to the VIN which takes into account the version number of any affected module. Since those also change, the same software doesn't always work, so it needs that custom touch. As I'm sure you are aware, there are lots of computers and therefore code in an i3 to make everything work, and it needs the right versions to work together.
FWIW, someone said, I haven't checked with the dealer, that the courtesy charging plug unlock won't work with the earlier builds, and I'm sure there are other things that are slightly different as well. Mine was built the end of April, 2014, so one of the earliest ones delivered to the USA. I've had a few issues, but none that have turned me off from the vehicle. It is my daily (well, I don't drive daily!) driver, and my ICE may not get used for a month or more. Eventually, I may trade them both in for something that I like that can perform the long-distance, and the EV running around, so that the ICE doesn't need to be used for my mostly short trips.
