with the apple carplay, don't you need to just use the touchscreen instead of the phone?

 

Yes, that’s true.

 

You can use both. However, C2Play seems to work without any delay it you change "wifi" calling to "non" in your iphone settings
Settings > Phone > Wi-Fi Calling. Turn OFF Wi-Fi Calling

 

As well as with Android Auto. However, there are certain things you may want to do on your phone's screen (when you are not moving, of course!) For instance, quickly scroll through your emails. Or dial a phone number while your touchscreen is displaying the car's satnav screen. Or, just get better GPS and cell reception.