Your car’s position does not change simply because it disappears from a mirror. What changes is how much of the surrounding road you can see.
When your mirrors are angled too far inward, you may use valuable mirror space to display an area already visible elsewhere. Angling them farther outward can redirect some of that space toward traffic approaching alongside you.
Ideally, a vehicle passing you should move from the interior rearview mirror into the side mirror and then into your peripheral vision as it draws alongside.
The transition should be easier to follow, with less risk of the vehicle disappearing between the views.
This is the main advantage of the technique: it aims to reduce the gaps between your mirrors’ fields of view rather than simply making the rear of your car easier to see.
It does not mean every blind spot disappears in every vehicle. Car design, mirror size, seating position, and the driver’s height all affect visibility.
