How to Be Courteous on the Road Without Saying Thank You the Whole Time

The rules of the road change wherever you go. You can be courteous to your other road users without saying thank you all the time. Maybe it's a body language. Maybe if someone didn't say thank you to me, but they, I could see they were smiling. But with blacked out windows so rarely you can't see the fizzog of your adversary until they're almost right next to you at which point they've not said thank you and you want to go. Chris: Do you think there's car language though also that says thank you there, Chris?