Would you own a car that has an associated app for a phone or tablet?

The app would do things like planning trips, showing mileage statistics, giving you verbose errors in case the vehicle has issues, and for an EV you could plan and control charging for off-peak times, etc.

If you would like that, why wouldn't you like the same in the car itself? Those are not things you would need to use while driving, of course, but it would still be quite a bit nicer that going to "stats menu 001" "L" "2" "11" and viewing a number on some LCD readout...