I imagine a car's sensors could be more accurate than a phone's because they're in a fixed orientation. Plus it can tell if you're turning the wheel and should

I imagine a car's sensors could be more accurate than a phone's because they're in a fixed orientation. Plus it can tell if you're turning the wheel and should have the same distance info that the odometer gets. The OBD-II data should include odometer readings. I assume phones could at least get that via bluetooth dongles, but I'm not aware of any nav apps that do.