Just a quick update - will note that I've had CarPlay crash about 4 times now, usually during startup. Most of the time it comes back in about 30 seconds, but I've also had to turn it off and on again.
Also, someone else seemed to check and looks like the split screen functionality in CarPlay only works with Apple Maps
but again, I prefer to have maps on the entire screen. Once I've started listening to something I don't really see the purpose of it taking up screen space to tell me what I'm listening to.