How to stop car windscreen freezing

Here's how to stop your car windscreen from freezing and top tips for defrosting your car

How to stop your windscreen freezing:

• Rub a raw onion half on your windows and windshield the night before a big freeze. This strange car trick will keep frost from forming on the glass.
• You can also spray it with vinegar or alcohol mixed with water to avoid frost. Try a 1:2 ratio of water to alcohol.
• Cover your windshield with rubber bath mats or a folded sheet - don't forget the carrier bag to put it in once you remove it. Use your windscreen wipers to keep it in place.
• If its the blades freezing rub them with alcohol - it keeps them from sticking to the window.
• You can also use night-before de-icer to make your life easier.

What not to do

• Do NOT use newspaper as it's too thin and can freeze onto the windscreen.

  How to defrost - and deter opportunist thieves

  Unfortunately, opportunist thieves come out to play when commuters are defrosting their windscreens. On a particularly cold day in November 2016, a car was stolen every five minutes as motorists left their motors running unattended.
  Dean Hill, AA AutoWindshields technician of the year, said modern cars are very difficult to steal without keys, but added: "To car thieves, frosty mornings are a gift."

Fortunately, the AA has a handy guide for drivers. The seven-step plan makes for a quick de-icing, so people can be on their way.

The first rule to remember – after turning the car on and warming the windscreen up from inside with the hot fan – is to stay clear of using water, hot, cold or otherwise.

Instead, us a salt solution, commercial de-icer, or alcohol. Having a good scraper is also crucial.

It's also worth taking preventative and ongoing measures overnight, such as covering your windscreen and filling your car's water reservoir with some alcohol.

Here are a few points from the AA you should consider when defrosting:

1. Stay with the car all the time - if you must go back indoors switch off and lock the car.

2. Do not drive off until all of the glass is clear

3. Remember not to leave wipers in 'auto' when frost is expected - if wipers are frozen to the glass the wiper motor could be damaged. Don’t try to force frozen wipers off the glass

4. Never use just-boiled water to clear glass – it could crack the glass, freezes quickly and could ice your wipers to the glass

5. Clear all snow off the car, a soft brush is effective – making sure the front grille is clear (otherwise there is risk of the engine overheating). Make sure lights are clean and working

6. Air conditioning isn't only for summer - it will help to dry the air and keep cold glass mist free.

7. Don’t use your hands to wipe misted-up windows – you'll leave greasy smears and a diamond ring could scratch the glass. Use a lint-free absorbent cloth if necessary.

Why does frost form on cars?

The temperature doesn't have to drop to below freezing for frost to form.

When you switch off your car the temperature inside the car drops. The ground temperature can be colder than the air around it, and the glass tends to cool quicker.