When your windshield builds up a nasty film, it can become dangerous to drive. You won't be able to clearly see out of the windshield. A build up of film is also harder to remove since it has happened over time. You can't just use soap and water to get it off. There are, however, ways to clean the film off of the windshield so that you can see again.
Buy a box of Mr. Clean Magic Eraser. It will cost you about £3.20, but it is worth every penny. It gets film off of any surface, including your windshield. The best part about it is that you don't even have to scrub hard. Just wet the eraser and wipe across the windshield.
Use Greased Lightning. You can buy Greased Lightning at any grocery store. All you have to do is spray it directly on the film on your windshield. Let it sit for two minutes and then wipe away with an old rag. You will need to clean your windshield with Windex afterward because the Greased Lightning will leave streaks.
Consider using Bon-Ami, which is a cleanser that will remove the film on the car windshield. What makes Bon-Ami unique is that it is all natural and contains no harsh chemicals. Once you clean the film off of the windshield you will need to use some Windex to get the glass to shine.
Pour rubbing alcohol over the film on the windshield and let it sit for a few minutes. Grab an old rag and start rubbing the windshield in a circular motion. The film will then come up. Wash the windshield with dish soap and water after you get the film up. For a nice shine use Windex.
Purchase a can of cola and pour it over the road film. This is a cheap trick that works very well. Give the cola a few minutes to eat away at the film and then wipe off with a rag. You will need to clean the windshield with dish soap and water after this and then finish off with some Windex and paper towels.
Go through a car wash first to see if this gets the film off. This will cost anywhere from £1.90 to £6.