He is not a little kid. You are not his mother.

I would not be off and on with him, just taking a "break" from him; I would do like you did with the car and put things in park, immediately and not care about his "answer"/excuse for his behavior. You told him the car was not moving until he quit screaming, etc. and, I trust, the car did not move until. . .

I would decide (and tell him) that you are not interested in his "excuses" or rationales, you cannot be around him if he is going to be annoying, that you find him passive aggressive and that you feel he might benefit from therapy but, in the meantime, you will give him three opportunities to behave each time you are with him but on the third one, you will leave him for the day/period of time.

Eventually I bet you get to only 3 pull-overs-and-put-in-parks, at which time you can reduce it to 2, then 1 and by then, maybe he'll have learned to get along with people better?

If he acts like a child; treat him like a child with adult "time outs" of that sort. I love the car-in-park response. Just do it in every situation so he, hopefully, learns. And, when he is out of control for too long/many times in one visit, leave him by himself in his corner for a time out.