Missouri -
4. Mirrors: All motor vehicles which are so constructed or loaded that the operator cannot see the road behind such vehicle by looking back or around the side of such vehicle shall be equipped with a mirror so adjusted as to reveal the road behind and be visible from the operator's seat.
From:
§ 307.170. — Other equipment of motor vehicles--violations, penalty. - Missouri § 307.170. — Other equipment of motor vehicles--violations, penalty. - Missouri Code :: Justia
So I interpret this as, you don't need any mirrors at all as long as you can look out the rear window or stick your head out the side window and look backwards. Does that sound right to everyone else?