Would You Have the Courage to Say: Pay Me Whatever You Like?

I travel every week, and I often schedule a car service to go to the airport. The last several times I’ve gotten the same older gentleman who is charming without being over-bearing with conversation. (I don’t like too much chit-chat.)
When we get to the airport, I ask “What do I owe you?” Each time I get the same response, “Pay me whatever you like.”