Proper Side-view Mirror Position

I was read a post on the tdiclub.com about side-view mirror positioning. I did a bit of research and found this from the US Department of the Interior.

To adjust the side-view mirrors properly, one moves slightly to the left and right of normal driving position, and adjusts the mirrors to just view the side of the vehicle. This can be accomplished by placing your head on the driver's window while adjusting the left side mirror, and by sitting in the center of the vehicle while adjusting the right side mirror.