the controls are anchored to the viewport edges (at the start of the layout), but then the car has scroll to which moves the camera to the bottom of the layout - so the controls are now way off screen.
since you want the controls to always be on screen, make a new layer, with parallax 0%, 0% (so that it doesn't scroll). put the controls on that layer - and move them up to the top of the layout so that they are within the visible area (above the dotted line).