Give comfort to your co-traveller.
Don’t think too much. I meant the actual co- traveller in your car itself.
Imagine you got a lift from your friend’s cousin, and you are not familiar with him/her.
Then how uncomfortable will it be if that person is not at all talking to you during travel.
You might feel so restless to travel with such a person, and feel just like put in an undeserved place.
(And the same situation plays even while travelling with a familiar one too)
Now imagine yourself as that friend’s cousin and think how you will act with your co- traveller..