Thought this might be a decent place to share my thoughts on the placement of car side view mirrors, as most real-life conversations I've had on this are met with slight annoyance. I learned this from Car Talk on public radio, and in the years since it still seems as though 99%+ of drivers do not have their side view mirrors positioned correctly.
The point is to eliminate the blind spots between the rear view mirror and your peripheral vision. Nearly everyone has the sides set up to look... directly behind the car. So now, they have 3 rear view mirrors, and the concept of "side view" is lost. If you're right behind a car and you can see their entire face, it's poor placement. We were actually taught this in drivers ed; Barely see the side of your car on each side mirror when sitting straight up in the driver's seat.
The correct way to do this (in cars with the wheel/driver on left) is to put your seatbelt on, lean your head allllll the way to the left so you bonk it on the window, and adjust the mirror outward to line up the edge of your car. Then lean allllll the way to the right like you're right in your passenger's face, and adjust the mirror outward to line up the edge of the car. When it's perfect, a car coming up behind you and passing you will perfectly move from the rear view mirror into the side view mirror and into your peripheral vision with zero blind spots.