So if Viggo's son had just stolen the car and not killed the puppy
John Wick would have placed a call to Viggo, told him what happened, Viggo would have slapped his son around and told him to return the car and who he stole it from and what would happen if he pissed Wick off, the car would have been returned and the puppy would have grown up to be John's best bud.
End of movie.