Adjusting your car's side view mirrors

Start by setting your rearview mirror as you normally would.

Then, lean your head all the way to the left, so it touches the driver's window. From that position, set your left side-view mirror so you can see the back corner of your car.

Then lean the same distance the other way, and set your right side-view mirror the same way.



Source = https://www.cartalk.com/content/about-six-months-ago-you-talked-about-adjusting-outside