I"m really sorry you are going through all of this with your husband, the back and forth is really hard. It's not nearly the same as a new car, but a week after I told my ex I didn't want to be married anymore, he brought home a labrador puppy, maybe in hopes that it would keep us together? I'm not sure. I had agreed to go to counseling and gave him 2 months to see if things could change. Point is, I ended up with the dog 6 months after I moved out of the house because he couldn't take care of her. I didn't ask for 'dog support' money in the divorce so she is an extra expense I had not planned for when working out alimony. If you agree to buy a new car and things don't work out, can you afford to continue paying for the car? or do you end up giving it to him and you possibly have no vehicle?
that is of course worst case scenario.