The best part's when Leslie stops his car at the finish line. This not only helps prove his love, it also shows that he's learned a lot since the movie started.
Maggie: What are you doing?
Leslie: Proving that I love you.
Maggie: But you'll lose the race!
Leslie: Can you think of a better way to prove it?
Even though Fate and Max cheat and sabotage Leslie's efforts to win the race. When it comes down to lives being on the line, they are actually good people at their core (not that they'd ever admit it).
When both teams end up caught in a blizzard and later on an ice floe they willingly combine resources and work together to survive.
Also, after they are captured by the Baron and forced to impersonate the Prince, Fate flat-out refuses to help the Baron. Only when his life is threatened does he (understandably) go along with it.
Max catching the wedding bouquet that Maggie threw looking genuinely happy for the recently married couple. During that scene, from the look on the Professor's face, he's trying very hard not to show that even he's happy for them too.
The Thomas & Friends special:
Thomas and Ashima's duet "You Can Only Be You".
As the engines depart Sodor for The Great Railway Show, as they pass through Vicarstown Station, a cheering crowd sees them off, wishing them good luck. As Emily passes by one little girl waving the Sodor flag as she cheers them on, she smiles warmly at her.
Once the Sudrian engines and Ashima arrive at The Great Railway Show venue, Ashima offers wishes of good luck before breaking off from the others. She may have spent more time with Thomas, but still had a chance to meet Emily and the others at some point while on Sodor as well.
Ashima: Well, we're here! So, good luck, everybody! And may the best engines win.
Emily: Thanks, Ashima. Good luck to you too!
Percy was too scared to compete in the shunting race, so he lets Thomas step in. Emily also offered Thomas some encouragement as well since she and the others were unable to win, and they hoped Thomas would be able to make them and Sir Topham Hatt proud.
Depite Ashima winning the Race, Thomas also managed to win for sacrificing his victory to help Ashima when he sees she's in trouble.
After The Great Railway Show is over, with no sign of Ashima, despite efforts by Emily, Percy, and the others trying to find her, as the engines depart to return to Vicarstown and Sodor, Thomas finds her at the coal hopper singing the tune of their earlier duet, and suggests she come back to Sodor with him, Emily, Sir Topham Hatt, and the others and catch her rail ferry back home to India from Brendam Docks. Ashima happily accepts.
Ashima: Good idea! You are clever. (winks) Sometimes.
Then the reprisal of "You Can Only Be You", "Be Who You Are And Go Far", is sung by Thomas, Ashima, Emily, James, Philip, Gordon, Percy, and Henry as they return to Vicarstown Station to a cheering crowd welcoming them home alongside Toby, Henrietta, Oliver, and Toad.