Here's one I heard on the radio that makes a huge difference in what you can see out of your door mirrors:
Drivers mirror:
Whilst seated in your driving position push your head against the window and adjust your mirror so that the inside of the mirror just see's the back end of your car.
Passenger mirror:
Again whilst in your driving position move your head / body to the middle of the car and adjust the mirror so that the inside just see's your back end (of the car).
You will be amazed that in conjunction with your main rear view mirror you will not end up with any blind spots.
Absolutely amazing
Try it and see.
Oh, one down side - reverse parking becomes alot harder
