i hate how the seatbelt locks when i want to scatch my balls or something.
adding on to what arnold said... pretty much there shouldn't really be overlap between your mirrors. ie you shouldn't see the same car in the left side of your rear view mirror and the right side of your left side view mirror.
people forget that the mirrors on the sides are actually called 'side view mirrors' meaning they are supposed to actually allow you to see what is to the side of your car, not the back.
If you pass a car you should be able to see it enter your side view mirror, then pass into your rear view mirror without overlapping.
How To: Adjust Your Mirrors to Avoid Blind Spots - Feature - Car and Driver