There's a simple, gets-under-your-skin issue with CarPlay in cars that can show CarPlay stuff on two screens: you're forced to view turn-by-turn directions on one screen and a route overview on the other.
What do I mean? Take a look:
I'd love to be able to see what's on the left also on the right. Why?
First, because it's great for passengers to be able to see where we're headed. The route overview screen (currently on the right) can sometimes be so zoomed out you don't have any idea what is actually happening. Confusingly, it doesn't communicate your progress through the route because it constantly rescales the map as you drive to keep the route the same visual “size.” In other words, if you've driven five hours of a ten hour road trip, you'd think the route overview screen would show your arrow halfway across the screen, but it doesn't. Instead, it keeps looking like you've just started the trip with your arrow all the way on one side and the destination all the way on the other.
Second, because for some inexplicable reason, Apple Maps doesn't show the next turn-by-turn instruction on the dash map. Take a look at that picture and you'll notice that the screen on the right says "Start on Campus Dr" and the screen on the left doesn't. If you switch your main screen to listen to music or a podcast, you're out of luck! You can't see the next turn-by-turn direction even though CarPlay is aware that Maps is open on the dash screen only.
If you simply try to switch the main screen to be turn-by-turn too, the dash screen changes. And vice-versa. Here's a video showing this behavior in action:
This is just the kind of small, simple, and frustrating issue that you think about every time you drive and get to believing would be an easy fix: if we can't have turn-by-turn directions in the dash then at least let us switch each screen to our own liking.
Now, this doesn't mean I don't think Apple Maps is great, because I do. As an app it has reached almost a platonic ideal of beautiful map styling, reliable directions in the US, and enjoyable features like Share ETA. Where the development of CarPlay's usability has stalled, I can only hope the cause is work being done on CarPlay 2 .