At the beginning I couldn't get used to them and didn't dtrust them much. Now, I use them when I am parking in front of someone, at parking lots and when backing up. They are great!!!!
They are great. They are most useful when you are parked next to vehicle larger than the 4Runner. It just takes some getting used to. These mirrors actually saved me a couple of weeks ago when an extended cab pickup parked next to me.
Nevermind. I just read the other thread about it. Mine doesn't come with them. I'm having a rear view camera installed, so hopefully that should help me out in the backing up department.