1 empty (clean) gallon jug
1 gallon water
1 tablespoon dish soap (use whatever you have on hand. I used Dawn)
1/2 cup non-sudsing ammonia (Note: You can substitute vinegar for ammonia if you prefer)
A few drops of blue food coloring (this is optional but I think it’s a good idea because it serves as a reminder/warning of the contents)
Fill an empty gallon container with water. (This is a good way to repurpose 1 gallon plastic vinegar jugs, which I seem to go through a lot of!)
Add, dish soap, ammonia, and food coloring (optional). Recap the bottle and gently tip upside down a few times to mix ingredients. Pour into the windshield wiper fluid reservoir of your car.