The box for the head unit swivels toward the passenger or driver. To make it tight I used thrust bearings - they are cheap on Amazon. This is the bearing setup just below the box - there is also a small one under the nut (the other end) This allows the bolt to swivel with the head unit and not loosen up. I may put a little swivel motor on it later.. I have also started making door handles.. The next project to start is the door panels.. I ordered 3 way separate speakers for the doors and will build them into an oak and aluminum door panel.. I'm waiting for the speakers to be delivered.