FWIW, the map data is really free, but to make it work, you need the FSC code, or it won't load. Depending on the market, you may have an FSC code installed that can handle more than one update, but in the USA, at least for now on the i3, an 'official' FSC code is only valid for one car for one specific version. I recently purchased a lifetime key for each of my two cars. We'll see how it works on the next update...in theory, it should just load without stopping and asking for the FSC code to be entered. Typically, in the next 60-days or so, the new maps will be available for most markets.
BMW had announced last year that newer cars would get free OTA updates, but it was being phased in as they supplied newer cellular tech for the car. The older stuff used tech that was too slow to be reliable for the volume of data needed. On the i3, if I remember, the update did not fit on a 32G USB drive...I had to use a larger one. OTA updates could be done in chunks, verses all at once as is done when you use a USB drive. Make sure it is formatted in FAT32, or the car won't recognize it.