If your car windows have bugs and dirt that have hardened on, they may not come off with a standard window cleaner and you'll be stuck with a dirty car windshield. If this sounds like you try making your own car window cleaner by mixing up a mixture of baking soda and dish soap. Mix with a ratio of 70% baking soda, and 30% dish soap and stir the ingredients into a paste. Use this paste on your windshield with a little bit of water and scrub. I've found that this mixture removes even the most baked on bugs from my windshield.

One thing to be careful of though, this mixture is not good for the paint on your car. Don't use it on your paint. And when you are done, be sure to throughly wash the mixture off your windshield and car using a garden hose.