Did you try adjusting your side mirrors outwards so that when you're seated comfortably in the middle of your seat, you can't see the sides or rear of your truck. In order to see the sides or rear of your truck, you must move your head left or right about six inches.
This helps out a ton for me. In fact, if a truck is directly side by side with you, you can actually see the rear of that truck in your side mirror! YMMV.