Safe driving advocates tell us that being able to look out the car's windshield before you get behind the wheel is a top priority. In winter climates, thanks to frost buildup, that can be a bit of a problem.
However, you can probably take precautions with the onions you have in your kitchen.
According to Today, you can cut an onion in half and rub it against your windshield to keep frost out. When water or snow comes into contact with glass, it becomes difficult to form hard ice.
The same principle applies when wiping the car with potatoes, but it is better to wait until the neighbor has returned to the car before doing this.
This is most likely safe on a car windshield, but it's a good idea to try it on a small test spot first. be careful. These are corrosive and can damage your glass, your car's finish, or both. Hot or boiling water is even worse. You can see outside through the windshield, but that's because it's shattered.
[h/t Simplemost]