How to Clean the Inside of Your Windshield

We all have seen it. That gross, cloudy film that suddenly appears on the inside of your windshield. No one ever notices it until driving directly into the sunlight, when the film decides you don’t need to see the road anymore. And no one ever thinks to clean it off, since it rarely makes an appearance.

Not only is it terrifying, not being able to see the road when your driving, but it can also be a driving hazard. What causes this mysteriously appearing film though? When your windshield was new, the film wasn’t there. So, what causes this icy film to build up and how can we get rid of it?

The (not so) mysterious film

All good questions and I, thankfully, have some answers for you. That film, as mysterious as it may seem, does not suddenly appear on the windshield right as we are driving at the sun.

In fact, the formation of this cloudy layer is a gradual process that takes time and heat. There are several things that attribute to the build-up of this film, one being smoking.


Surprise! Smoking causes smoke and when one is in a confined space, like a car, the smoke particles tend to leach into every material inside. This is a simple process of diffusion or osmosis.

The windshield happens to be an object that is 1) right in front of your face, and 2) has a very large surface area. It’s only natural that smoke particles would stick to and leech into the windshield.

Dust & Dirt

As fewer people are smoking these days, the above cause is probably not something most people must worry about. However, regardless of who the person is, or how hygienic they are, dust and dirt will always be prevalent. Like smoke particles, dust and dirt go everywhere but unfortunately, the windshield happens to be one of the most visible places it goes.

Greasy Outgassing

This is perhaps the main cause of that film developing on your windshield. What is outgassing though? Well as many know, plastic and vinyl in cars are made of crude or synthetic oils.

Though your dash should never feel greasy, the plastic or vinyl in vehicles often break down and leech oil over time. High temperatures will also speed up this process.

The problem with this deterioration process of car plastics is that the oil products that are outgassed are not visible to the naked eye. As the name suggests, the oil is released in a gaseous state and those gas particles tend to stick to the windshield, creating that gross film. And since it’s a type of oil, it can be even more of a challenge to clean than with mere water.

How to fix it

Unfortunately, there is no surefire way to stop outgassing from occurring or dust and dirt from seeping to the inside of your car, however, there are things you can do to slow it down and clean it up.

First and most obvious, if you smoke, you need to stop…for so many reasons. Second, park your car in a garage. Not only will this reduce exposure to high temps causing more outgassing, but it will also reduce the amount of dirt that gets in your car. Lastly, always try to park in shady spots, the hotter your car gets, the faster the outgassing.

Clean it

Once again, regardless of what you do, this film will eventually build up on your inner windshield. But, we can offer some ways to effectively clean it off. For all of these solutions, lay a towel down on the dash/area to avoid damage.

  • Give classic glass cleaner and a microfiber cloth a try. You might not need to go full throttle if the layer isn’t too bad.


  • Try some hardcore oil fighting dish soap, water, and a rag. Since this is most likely an oily film, simple dish soap could really be the solution.


  • There are products out there specifically for this purpose if you want to waste/spend money on these, go for it.


  • Crumpled newspaper is also rumored to work. I personally have never tried it, but it doesn’t hurt to try.


All in all, the film isn’t that complicated of an issue nor is it that difficult of a fix. Give all those solutions a try and if none of them work, come back and let me know and I will do further research on how to get rid of this nasty cloudy film. Good luck and happy adventuring.



Author: B. Delamater