When adjusting the left side mirror, where should you position your head?

Positioning your head close to the left window when adjusting the left side mirror allows you to have the most accurate perspective of the mirror's field of view. This technique ensures that you can see how much of the roadway and any vehicles that may be in your blind spot are visible in the mirror once it is adjusted. By being near the left window, you can effectively set the mirror to minimize blind spots, thereby enhancing your visibility and safety while driving. Adjusting the mirror from this position helps to establish the ideal angle for optimal viewing of the lane beside and behind you, which is crucial for safe lane changes and maintaining awareness of your surroundings.