All very good points.
I wish I had an answer.
since I bought the bolt as a weekend car, this battery issue has become more relevant since every time and I get in the car the phone is dead. As I start using the car as a more daily vehicle, when my other car finally Bites the Dust, I think that I will be fine since low-power mode may extended the battery just enough until the next time I start rolling again, and so the phone starts charging again.
The other thing I wish the iPhone could do is stay in low-power mode no matter its status. As it stands, the iPhone will exit from low-power mode when it achieves a full charge. This is another sticking point which I wish had an answer.
Lastly, for users of iPhone 7, the official Apple battery case seems interesting. Does anyone know if this battery case can accept power and also transfer data at the same time? Most iphone battery cases I have seen require a physical switch to be selected to go from charging to datasync.
Anywho, since this isn't really a General Motors issue, I will go ahead and chalk it up to a partial solution to a permanent navigation system in the car. I still think it's better than having a outdated navigation system where the maps get old the second you drive the car off the dealer lot. I guess I will take the good with the bad.
Update:. I just confirmed that the official Apple battery case for the iPhone 6 and 7 both can support data and power at the same time without a special switch. For those users you want to enable a permanent navigation system in their car, having this battery attachment May provide the solution so you don't have to think about the phone anymore.