Friends dogs car obsession

So, my friends have a little chihuahua, I forget how old she is, but pretty young. Tink, the dog, has an obsession with cars. She will bark at them, try and run up to them and the such. She is not in the least bit scared of them. They don't want her to fear cars, but to stay a healthy distance away from them.

They are thinking of giving her to some one who has a fence, as they don't have one and they have to have her on a leash. They probably won't listen to this advice much, because they already are going to get another dog from a rescue. But I thought it would be helpful for them to hear, since they plan on training the new dog.

Thanks a ton!!

Put the dog on a long leash and as it runs up to the car call it and then if it won't come gently pull on the leash and when the dog comes reword with a tasty treat or a game.

Okay, I will tell them. Thanks!

Your welcome and if a car goes past and the dog ignores give it a treat or reward with what likes best.