Let’s get right down to it. If, when I drive up behind you, I can see your face in your side mirror up until the point where I can no longer see your side mirror, your side mirrors are not correct. Here’s the way it works — your rearview mirror, mounted on your windshield, is meant to show the view of what is directly behind your vehicle. Anybody with a trailer or other obstruction in your vehicle can promptly ignore the rest of this rant, as you are in that special case when your side mirrors have to serve double duty. We’re going to work through this, workshop-style. First, the purpose of your rear-view mirror. I’ll provide the disclaimer now that my illustrations are terrible and the angles and ratios are all wrong.
Simple enough. You look into the mirror, and you receive a view of the stuff behind your vehicle. Depending on your bent, you may view things slightly to the left or right, but that’s the point of it. If you’ve adjusted so you can see behind you, and you’re not seeing only your trunk or roof, you’ve probably got your rear-view mirror about right. I shouldn’t have to say it, but if you’re staring at yourself in your rear-view, you’re using it wrong.
Now comes the point. The side mirrors are meant to see behind and aside your vehicle, and remove the mythical “blind spots.” A properly adjusted set of mirrors has virtually no blind spots, as the very small region that would be missing in your vision soon enters your peripheral. Here’s how it’s supposed to look:
So we’ve got all of the mirrors covering different regions of space, so you get to maximize the utility of your mirrors. Now you can see people creeping up in your blind spot, and the only blind spot that exists is a region very close to your car on either side, and you will see people entering it in your side view mirrors so it will not be a surprise. Yes, there’s a little separation between the views; this is for clarity, but as they get further out, the two almost converge. What about the gap when they’re closer? It’s not a problem; no vehicle is small enough to get lost between the two; you’ll smoothly watch one roll from a side/rear mirror to the other. I’m not going to bother illustrating this fact, but the mirrors should be aimed back at a similar effective elevation and angle as the rear-view, so you see cars, not the sky, not the road. I’m not going to get picky on this, there is a correct point, but we’ve got bigger fish to fry, namely this:
Mr. Yellow and Mr. Blue may now eat your children because you can’t see them! You’re too busy staring, THREE TIMES OVER, at your car and the guy behind you, because that’s all that you can do. Unsurprisingly, I usually see this mirror configuration on an SUV, but it’s not confined to that particular crime against humanity. If I had the patience, I’d also illustrate out that most of the view of these mirrors is blocked out by your vehicle, rendering them redundant and useless. Normally, I’m a fan of redundancy — redundant power supplies, control circuits, network connections … that sort of stuff makes sense. Redundant mirrors make no sense. If your windshield implodes and you lose your rear-view, you can adjust your side-view mirrors to view rear for that moment in time.