Dick van Dyke singing You Two. He's perfect at playing a loving father.
Chitty having been turned from a burnt-out heap of old iron into a beautiful car yet again. Further heartwarming moments as Chitty starts up again and as Chitty gets back out on the road.
Caractacus expressing complete confidence in Chitty during the journey to Vulgaria:
Truly: Where are we?
Caractacus: Somewhere over the North Sea, I think.
Truly: Don't you know where we're going?
Caractacus: I don't, but Chitty does. I think we're in pretty good hands.
Caractacus and Truly among the hidden children of Vulgaria. They've never met these kids before and technically have no obligation to help, but they take very little convincing, if any.
While Caractacus is singing Hushabye Mountain, he stops in the middle. He's trying to tell Peter to not lose hope, but he seems to have lost it himself. Then Truly comes in and continues the song, leading him to join in on the last line and regain his fire.
This little Brick Joke near the end, right after Caractacus and Truly kiss.
Truly: *outraged* Well, Mister Potts!
Caractacus: *shocked* What? What's the matter?
Truly: *laughing* Now you'll have to marry me!
The following exchange. If nothing else, you get the feeling that Caractacus wouldn't say that last sentence out loud to just anyone. It's a secret that he's trusting her with:
Truly: I really owe you an apology. You're more than just a father to those two children.
Caractacus: Nursemaid, private tutor, chief cook and bottle-washer, everything. Except what they really need.