Just keep telling yourself I'm not going to be petty. I'm not going to be a pushover either. I say give the stupid phone back. You have another one and who cares. It's like parenting. You have to pick your battles and it's probably not a battle worth picking. The car might be. If she isn't paying for the one car and you are then you should be the one driving it. You aren't leaving her without a car. I know that can be a pain transfering car seat and such, so you decide which is better for you and the kids! All decisions from here on out should be based on what is best for the kids.