4 PCS Car Rearview Mirror Waterproof Film, Rainproof Anti Fog Auto Side Window Protective Sticker for Safe Driving, HD Clear Nano Coating Rear Mirror Film for Most Vehicles (Side Window)

I cannot see any point to this product. I really don’t see any difference between water beading on the mirror with or without the product. (See photos.). Installation was easy enough. Instructions and other reviews said to spray water first. That didn’t seem to make much difference, except that the right mirror which used water has a large bubble in it. Applying without water did produce a fair amount of air bubbles which were difficult (but not impossible) to get out with the included squeegee. Perhaps my aggressive squeegeeing altered the water repellent quality? Who knows, but I’m going to just remove and dispose of these. As for size, I ordered the smallest but still had to cut a bit off so it fit my mirrors.

I installed this anti-fog/anti-rain film on my truck windows tonight. The install is straightforward, almost identical to a screen protector install. The kit does include some glass cleaning/drying wipes which is a nice addition because clean glass is essential to avoid bubbles. The second backing is also blue which is super helpful so you can easily see exactly where you are positioning it (this backing is of course removed after installation). Definitely wet the glass before placing the film as the directions state; it will make it much easier to get it in the right place! On the second mirror I did get a few bubbles which I removed with a small plastic squeegee. After install, in most light the film is barely perceptible; however if the sun is coming from behind you will notice the film.Since we have dry weather for a few days, I did an inside test by dousing the mirror with a few heavy sprays from a spray bottle. The water did indeed bead up and run off the area with the film much better than on the mirror glass. Not perfectly, but much better than the glass alone. It seems that where I had touched the film after install held water drops more than where I hadn’t. So keep it clean!Then I did another test; I coated half of the mirror with Rain-X, a common coating to repel water. Part of this section included mirror glass with the film and part without. I doused the mirror again with sprayed water. The effect of the film alone, the glass with Rain-X, and the film with Rain-X was all similar: much of the water rolled off.Update from actual driving in dry and snowy conditions for over a week: Snow sticks to the mirror like normal; film or no film. The film seems to attract more dirt. It's easily wiped away though.My conclusion:• Yes, this helps with wet conditions, but it’s not a miracle. It’s also low cost.• You can choose if you prefer this or Rain-X. The film only covers part of the mirror but you can treat the whole mirror with Rain-X.• In snowy conditions, there is no difference from a bare mirror• Where I used the plastic squeegee, the film did scratch some. I’d recommend this more for wet areas than snowy areas (like where I live) since an ice scraper may scratch it too• The benefit to me is very little so I will leave it on but wouldn't replace it