I am actually a driver but I'd love to hear other drivers' opinions. I am sure passengers, at least the considerate ones, care also.
I think it's rude and disrespectful when anyone talks on the phone in a car, while there are others around. None of us can talk or have our own conversations. All we can hear is one person talking. When this lasts the whole ride? It's quite hell.
So my question to you fellow drivers is whether you mind if passengers talk on their phone.