First, she could not talk in the car. This was brilliant. It relieved an enormous amount of stress from me. If she did, she put one hand over her mouth. If she tried again, it was both hands. If she still insisted, she put her head in her lap. We rarely get beyond the first hand.
There are times when she is relentless in the car but they are few.
She has a mat that is her playground. She has three activities she can do: Legos, read a book, or color. This is a LIFESAVER. This alleviated me having to entertain her, wonder where she was or what she was doing. For her, it allowed her to focus, not have to worry about making decisions and she was reaping the benefits of being compliant. I could also sense, instantly, she felt safe knowing she had a place to go. I know she welcomed the structure because she rarely leaves the mat or talks which both result in playtime being over. As she maintains compliance, I expand her playthings. Eventually, I will give her the choice of what to play with and also, expand her play area to a room. I don't know if this process sounds logical to you, but for most people that came to our home it seemed cruel and unusual. Unusual, yes. There is no way my other seven year old would stay on the mat. Cruel, absolutely not. But I think, with reason, it makes guest feel uncomfortable when they don't have the reasoning behind it. Because on that mat, playing quietly and smiling she does "appear" to be a perfect child. The best analogy I have is she is like a plastic flower. She is quiet, doesn't move and looks perfect. But sadly, that is all there is. There isn't a lot of emotion underneath it all. Yet.
She cannot ask for anything. I decide what she will eat and how much. I get her up in the morning and chose what she will wear. The purpose of all of this is, besides saving me a huge headache, is teaching her to trust me. I need her to trust that I will meet all of her needs without needing to ask me for everything. Eventually, we want to get to a place where she has choices between two things and then when she can, just completely choose for herself.