I have seen a few posts that are older and before ios 10 about this issue but no resolution. I recently got a wifi hotspot in my car with 3gb of data. When my iPhone connects it treats it as an unlimited connection and not a metered mobile hotspot. So photos and backups happen over my 3gb connection. I do have my phone plugged in to USB to play audio using my car speakers and to charge my phone. Has anyone found a way to tell the iPhone to treat a Wifi access point as mobile hotspot to save my data? I normally use 3-5gb of cellular data a month. When using the wifi hotspot in my car I used 2.9gb during a 1 hour car ride back from the Zoo.