A number of products can prevent car mirrors from fogging up, such as those made by ArmorAll and RainX. Use water repellents and anti-fog products to keep mirrors from fogging with help from a certified master mechanic in this free video on car maintenance.
Good afternoon, my name's Tom Brintzenhofe, a certified master mechanic out of Redding, PA. Today I'm going to answer the question of 'How do you keep your mirrors from fogging up?' Now there's a lot of different products out there that are made by different companies. RainX makes a good one. It's called Anti-Fog. Another one's made by ArmorAll, which is, they call it Clear Sight. It's a water repellent, and a anti-fog. But today we have a little RainX Anti-Fog on this rag, and a real simple way of applying it, just put a little bit, enough just to make it damp. And just go back and forth. I'm going to hold your mirror a little bit. Now all you gotta do is basically just rub this thing in. You know, rub it in pretty good, make sure you got a decent coat on it. It doesn't have to be running off your mirror, just enough that it makes it damp. Set that off to the side. Grab yourself a nice, clean, dry rag. And wipe this off. Try not to get your fingerprints on it. And that's about all there is to it in trying to keep fog off your side mirrors.