Keeping your car windscreen and windows clean isn't just smarter and more hygienic, it's essential from a safety point of view.
Dirt, streaks and smears can reduce visibility, especially at night or in adverse weather conditions when the lights of oncoming cars can get distorted in grimy glass.
Follow our advice for caring for your car's windscreen and windows, and how to avoid unknowingly breaking the law...
Make sure your car windscreen and windows are legal
The MOT test is an annual check on the roadworthiness for most vehicles older than three years. Your car may fail its MOT if:
The wipers in conjunction with the washer jets are unable to clear the windscreen.
The windscreen wipers are missing, insecure or in poor condition; and the washers are not functioning correctly.
The windscreen is chipped or cracked. The maximum damage size is 10mm in the driver's line of vision and 40mm within the area swept by the wiper blades.
Drivers hoping to pass their MOT should make sure windscreens are repaired or replaced before an MOT test takes place.
MOT examiners check the driver’s field of vision through both the windscreen and front side windows. If visibility is significantly affected by items such as misplaced sat navs, air fresheners, stickers (including parking and disability permits) or even a broken sun visor, this could cause your car to fail its MOT.
How to clean your car windows
Car windscreens and glass are difficult to clean compared to household glass surfaces. Exterior windows must cope with insect splats, tree sap, grease, oil, salt, dust and dirt, while interior glass is subject to everything from finger marks to pet slobber, dirt and grease.
Advice differs, but the length of time and the amount of effort needed to clean glass is entirely dependent on how dirty your windscreen and windows are.
For exterior glass, first lift your wipers away to give yourself easier access, then use hot water and a soft brush to remove surface dirt. If that isn't enough, use a car shampoo with a microfibre cloth or sponge.
Rinse off and dry with a microfibre towel. If time is short, or you prefer, use a glass cleaning solution and finish off with a microfibre towel.
There are a multitude of products available, not just to clean car window glass, but also to protect your windscreen against the elements, such as rain-repellent spray.
If you'd rather avoid a chemical cleaner, then many motorists swear by white vinegar diluted with water and a clean cloth.
Cleaning the inside of your car windscreen and windows is more challenging because it's here that smears and streaks are more obvious, and annoying.
Again, use a damp microfibre cloth and a cleaning fluid if necessary. Initially wipe the glass in a circular motion, then use up-and-down, followed by side-to-side motions. Now use a dry microfibre towel to finish off and remove any remaining streaks.
Whichever method you use, always clean your windows in the shade or in cooler temperatures so your shampoo or cleaning fluid doesn’t dry before you can wipe it off.
Read more: When will petrol cars be banned?
How to stop car windows from fogging up
Most drivers experience condensation inside their car to greater or lesser degree. Annoyingly, it often strikes on cold, damp mornings when you're in a rush to get on the road.
Condensation forms when warm air containing moisture meets a cold surface, such as your car window, forming a mist on the inside of the glass.
How to stop inside car window condensation - top tips
Damp inside your car can lead to condensation, so the more you can do to avoid this happening, the better. Unfortunately, the older your car gets, the more susceptible to damp it will become.
The most common way to get rid of condensation inside car windows is to turn on the heater, and heated windscreen, if you have one.
Turn on your blower full blast, but without heat initially, and aim it at your windows. Gradually increase the heat over a few minutes.
Also switch on your air-conditioning system to dry the air.
Remove unused, sometimes wet, items than can increase the level of dampness, such as cloths, dog blankets, towels, boots, coats, cushions, umbrellas - and even old coffee cups.
Check for leaks around windows, doors and sunroofs. Feel around the footwells for any dampness in the carpet too.
If you have off-street parking and you're prepared to keep an eye on your car, leave the windows and doors open to thoroughly air your car on a dry, sunny day.
Keep your windows clean, inside and out, because as grime accumulates it gives moisture something to cling to.
Place moisture-absorbing items in your vehicle. It may sound odd, but filling an old sock with cat litter has even been recommended because the clay particles help to absorb moisture.
If you'd rather steer clear of cat litter, buy a car dehumidifier bag, which is full of silicone balls that soak up moisture from the air inside your car.
Finally, if all else fails, invest in a small, battery-powered dehumidifier