It's not easy for a toddler to understand the big why's of not talking to strangers. After all, we meet people and greet people all the time with a smile. We try to discuss things with our 2 year old like I would with any older child with the exception that I know, they can't grasp it and we'll go over it again later.
So in this episode, # 47 0f Season 2, Robocar Poli, three kids from the town are lured into a truck with the promise of playing with toys. After the kids go in there, the car locks up his bed and traps the kids inside. It was a great opportunity to chat to my 2 year old, now going on 3, about the dangers of a stranger who promises candy, ice cream, or toys in another location. We'll chat about more in depth every time the episode comes on. Meanwhile I found it here.