How should the left side mirror be accurately adjusted?

Adjusting the left side mirror is crucial for minimizing blind spots and maximizing visibility. Positioning your head close to the left window allows you to see the side of the car in the mirror, which is essential for understanding the mirror's perspective and ensuring that you have a clear view of adjacent lanes.

This method helps to align the mirror in such a way that when you look at it, you can see the edge of your vehicle—indicating that you are also seeing the lane beside you. This view is essential when changing lanes or merging into traffic, allowing for safer driving decisions.

In contrast, the other methods do not provide the same level of visibility or accuracy. Being close to the rear seat or at a regular distance from the mirror does not give you a realistic view of the space around your car, while turning away from the window would obstruct your ability to gauge the position of your vehicle relative to other cars. Thus, adjusting the mirror with your head by the left window optimally sets up your side mirror for safe driving.