[MaddoxsMom]

1. avoid allowing them too close quarters, where an argument may ensue, i.e. backseat. Is there a way for you to keep them seperated in the car?

2. play "trade" when you take something from him, always have something better to give him in exchange, this was something taught to me by Ann Felske Jackman (the owner of my dogs sire) and this will help any possessive issues, eventually he will learn to give it up easy, because hes anticipating the object you are asking him to trade for. He will get to the point that when he has something of high value, he will want to bring it to you and show you, excited that you may have something better for him.

As far as him growling at your son, I think it would be difficult for anyone here to advise you on this since none of us saw what exactly the scenario was.