It's clear at this point that they don't want to, and frankly, the car is better for it. UI is fantastic, I don't need Google's UI messing with it.
If there was deep hardware-software-vehicle integration this would have never happened and would have been caught in testing. Unfortunately since CarPlay is developed in a disconnect from the display device, and insufficient testing is done due to the plethora of vehicles out there, bugs like this can and will happen.
Ironically, this is the antithesis of the common praise levied on Apple's "controlling both the hardware and software" approach.