Last Updated on November 6, 2021 by Stewart

Whilst this technically isn’t a glass cleaner, Rain-X Anti Fog does serve an important function during the colder months.

As the name suggests, it is a way to prevent your windows from steaming/fogging/misting up. Choose the definition the you prefer the most. This is for interior use only.


As with any product that is to be applied as a coating, the glass needs to be perfectly clean. You could use vinegar and water in a spray bottle and it’ll do a great job. I personally used Autoglym Fast Glass to clean the windows, but the choice is yours. As long as it’s a product that will not leave a film or a coating on the glass afterwards.

I folded up a microfibre cloth several times and applied a small amount of Anti Fog to it, before buffing it into the glass in overlapping circles and then allowed it to dry.  Unfortunately, the instructions don’t indicate how much product you need to use. As is always the case with detailing, less is more.

Initially, I did this with the doors closed in the car, and due to the temperature changes, the windows did start to steam up that weren’t treated. For the window that I was working on, the Anti Fog didn’t appear to dry. To resolve this, I fully removed the product, and applied the product again. This time though, the door was left opened. The Anti Fog dried extremely quickly and after touching it, there was no residue left over.

The same process was then used on the other windows in the car, as well as the rear view mirror. On the passenger window, I applied two layers of Anti Fog since this will increase the longevity of it.


I’m always a bit dubious about the claims some products make. One thing that stood out with Anti Fog though is that it doesn’t claim to completely eradicate any steaming up of the windows.  For the windscreen, I purposely only treated sections of it as a comparison to the non treated sections, and it worked exceptionally well.

On the side windows, there were a few small areas on the drivers side that did start to steam up, although it took quite a long time for this to happen. I’m chalking this up to there not being enough of the Anti Fog on the microfibre cloth. For that reason, I would recommend going over with a second layer to ensure that there is even coverage.

For the small amount of fogging on the drivers window, re-directing the fans in the car to the driver facing heater got rid of this in a few seconds. There was no need to wipe away the steam on the window. On the passenger side window, there was no steam build up at all. This was after a 40 minute drive when I had to re-direct the fans to remove the small build up on the passengers side.


The durability at the two week point is that it is as strong as it was when first applied. There is the argument that if there are a lot of people in the car, it may result in the coating being overwhelmed and therefore needs to be applied more often. However, for the low price of this (less than a Big Mac meal from McDonalds) and how quickly it is to apply it, it’s worth it. It comes in a 200ml bottle and I’d say that to treat the entire Clio, I used no more than 30ml. If that 30ml lasted for a month, the 200ml bottle will see you through an entire winter.

Rainx 81199200 Anti Fog Repellent, 200ml
  • Prevents interior fogging before it can start

Last update on 2024-06-13 As an Amazon Associate I earn from qualifying purchases.

  • Value for Money
  • Ease of Use
  • Results


Rain-X Anti Fog is a great way to prevent the build up of steam/fog on the interior car windows. It works extremely well and is really easy to apply.



Quick application gives great results

Easy to apply

One bottle will last a long time


Can leave a greasy film if not applied properly.