Why Put a Bag Over Your Car Mirror? Reasons Explained

If you’ve traveled extensively, whether around the United States or internationally, you might have noticed people putting a ziplock bag over the side mirrors on their cars. You may have even seen some clickbait ads promising to tell you the uses of putting a bag on your car mirror when traveling alone. We’re not here to waste your time, so we’ll say this up front, putting a bag over your car mirror has nothing to do with your safety while traveling alone! However, bags on car mirrors do have a lot of practical purposes.

Parking at home usually offers the benefit of a covered parking space, but that’s not always the case when you’re traveling or even just running errands. When you park outside, covering up your car mirrors with a plastic bag helps prevent all sorts of damage. This article will go over the various benefits of bagging your side mirrors, the types of hazards they help guard against, and why drivers might benefit from keeping a box of plastic bags in their trunk, just in case.

Why Put Bags Over Your Car Mirrors?

All sorts of disasters can happen to your car mirrors when parking en plein air. You may do your best to avoid it, but you can still be caught unaware by a sudden weather event or on an impromptu trip and wish you had some way to cover your side mirrors. This is where putting a plastic bag on your car mirror comes in!

Prevent Ice Buildup on Your Mirrors

If you live somewhere that gets a lot of cold weather, you know exactly how annoying it can be to walk outside on frigid mornings to find your side mirrors glazed over with a thick layer of ice and snow. 

While getting ice off your windshield is helped along by your vehicle’s windshield defrost functions, the side mirrors can be another story. You may be stuck scraping ice and snow off your mirrors for ages before you can even think about driving off to school or work. Throwing a bag on your mirrors before going inside in the winter is an easy way to keep them from getting covered in melting snow or rain, which will then freeze into ice!

Keep Rain and Morning Dew Off Your Mirrors

Finding dew or rain on your side car mirrors is a pretty regular occurrence in a humid or wet climate. Not only is it annoying to have to wipe down the mirrors on your car so that you can see, but depending on how often your vehicle is exposed to water, over time the moisture collecting on the protruding surfaces of your mirrors may actually warp the paint. 

If you’re not planning to continuously spray down every inch of your car with windshield water repellent, having a cover on your car mirrors will help keep rain and dew from collecting on them overnight. 

Prevent Condensation Spots and Desilvering

Have you ever seen a mirror with weird black edges around the outside or one that had weird foggy spots where it should have been crystal clear? This is due to a process called “desilvering”. Desilvering happens when the layers of a mirror peel away from each other and the backing begins to oxidize, turning black. This often happens when a mirror is repeatedly exposed to moisture. 

Even worse, when your rearview mirrors that are in the process of desilvering get wet, some of that water can get under the glass and between the layers, causing foggy spots of condensation that obstruct your vision. Once car mirrors get desilvered, you’re almost certainly going to have to replace them entirely. That’s why, if you’re going to be leaving your vehicle parked outside for a while, it’s a good idea to put a bag on your car window!

Protect Your Car From Birds

Car mirrors can present a very tempting perch for birds, sticking out as they do from the sides of your car. Unfortunately, birds don’t always leave it at that—they’ll often peck at the side mirrors or windows, or even leave a disgusting surprise caked onto your car door or side windows! Of course, this is most likely to happen when you park in the open air, whether at work, or in your driveway, or even while running an errand. Birds can damage the paint on your car and your mirrors, and even leave you footing the bill for a pricey repair!

Putting a bag on your side mirrors is an easy way to make it less appealing to birds. Not only will the mirrors be less shiny and likely to catch the eye, they’ll also appear to be—and actually be—less sturdy, so that birds that try to land on them will slip and give up. And of course, for those really determined birds, a layer of plastic between them and the mirror is a good barrier to protect your mirrors from getting pecked at!

Protect Your Wax Job

When you take your vehicle through a car wash or when it rains heavily, it might be putting your wax job at risk. The water that collects on your mirrors is not as easy to dry as the rest of the car, and it can, in turn, run down the sides of your car long after the rest of your car is dry, extending the amount of time your paint is exposed to water. 

Imagine investing so much in your car, taking it through the car wash to keep it clean, only for that to ruin the wax! Luckily, there’s a simple solution at hand. Just place some waterproof ziplock bags on your car windows before it rains or before you take your car through the car wash, then clean your side mirrors by hand so you can control the amount of moisture that’s getting on them!

Prevent Light Glare When Passengers are in the Car

Do you do a lot of errands with other people in the car? Have you ever had the experience of leaving someone sitting in your passenger seat while you run in to get something from a store, only to come back to them complaining about lights glaring off your car side mirror? Just place a bag on your car mirrors when you leave passengers in the car—it’ll keep light from reflecting into their eyes without you needing to endlessly adjust your mirrors when you get back to driving!


You might think the sight of a bag on car mirror is a little strange, but putting a bag over your side mirrors when you’re not driving is a simple, cheap, and clever trick for protecting your mirrors from the elements when you’re out and about. The next time you need to park your car somewhere that isn’t a covered carport, consider protecting your mirrors from the elements and from birds (and protecting your passengers from your mirrors!) with the simple addition of a plastic covering on your side mirror! 

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