Click here for a quick reference on how to set your car mirrors so as to eliminate that blind spot while driving on the freeway.
My siblings and I grew up in the Fifties/Sixties on a farm ten miles from town on a gravel road. Drivers of that era used their rear-view mirrors AND their side mirrors to see what was BEHIND them. I had no idea that the mirrors could be adjusted for freeway driving in a way that would make that nightmare experience a breeze.
Then I read how to PROPERLY set my door mirrors. Click on the link in my first sentence to read how to set your mirrors so that you can safely drive down the highway, using your mirrors to be assured you can move safely from one lane to the next without having to constantly turn and glance over your shoulder. If your mirrors are adjusted correctly, a car coming up behind you will appear in your center mirror (the one on the windshield). As the car passes you it leaves that mirror and will appear in your left (or right) mirror. And as it leaves that mirror it will appear in your peripheral vision (it doesn't hurt to glance slightly to the side at this point).
It took a few days of practice to begin trusting the mirrors but this revolutionized my driving experience. If you do a lot of highway driving and you have not learned this method, do it now. You will begin driving frantic freeway traffic with a lot less stress.