Seeing how LFS interface allows InSim application buttons to be moved around the screen, why not make mirrors adjustable directly from the cockpit during the race, without the need to accessing menus. Just click on the mirror you want to adjust and move it in the direction as if you used the lever.
I'm not sure if a 'drag'n'drop' is the right way to call it, but you get the picture
I'm not sure if a 'drag'n'drop' is the right way to call it, but you get the picture