Putting a towel over a car’s windshield is a common practice for many drivers. There are several reasons why people do this, mainly related to protecting the interior of the car and keeping it cool on hot days.
To Shade the Interior and Prevent Overheating
One of the most common reasons for putting a towel over the windshield is to shade the interior of the car from direct sunlight. On hot, sunny days, the sun beating down on the windshield can cause the interior of the car to heat up rapidly. This can make the car unbearably hot when you return to it later. Covering the windshield blocks out a significant amount of sunlight, helping keep the car’s interior cooler.
Studies have shown that shading a car’s windshield can reduce the interior temperature by up to 40-60 degrees Fahrenheit compared to leaving it uncovered. The lighter color of a towel also reflects more sunlight than the dark tinting on windshields. This reflective effect helps prevent the greenhouse effect that traps heat inside the car.
Keeping your car cool is especially important if you have children or pets that may be waiting in the car. It also prevents damage to interior materials from excessive heat exposure.
To Protect the Interior from UV Damage
Direct and prolonged exposure to the sun’s ultraviolet (UV) rays can damage and fade car interiors. UV radiation degrades and fades materials like leather, vinyl, and plastic. It also damages glass by initiating an etching reaction.
Covering the windshield helps block up to 99% of incoming UV radiation. This protects sensitive interior materials like the dashboard and upholstery from sun damage. It maintains the condition and appearance of your car’s interior for longer.
To Avoid Frost Buildup in Winter
Putting towels on the windshield can also help during cold winter weather. On very cold nights, frost can build up on the exterior and interior of windshield glass. Trying to scrape thick frost off the windshield can risk scratching the glass.
Laying towels on the windshield at night traps heat escaping from inside the car. This raises the exterior glass temperature, reducing frost and ice accumulation. The towel material also absorbs condensed water rather than letting it freeze on the glass. Less frost buildup makes it much quicker and easier to clear the windshield in the morning.
To Keep Prying Eyes Out
Some people use towels or other coverings on their windshields to block views into the vehicle’s interior. This is especially common in areas with high crime rates. A covered windshield prevents people from peeking into the car to see if there are any valuable items left inside.
A towel may also stop casual observers from seeing where car owners keep valuables while driving. It offers some extra privacy and security even when the car is parked in public areas.
As a Reflective Sunshade
Specialized windshield sunshades are designed to reflect heat and UV radiation. Some drivers use towels in place of commercial sunshades since they are cheaper and readily available.
Terry cloth towels can work effectively as DIY reflectors during the day. At night, they provide insulation against heat loss through the glass. The towel’s material and weave allow it to serve both purposes.
To Soak Up Morning Dew
In some climates, mornings often bring heavy dew accumulation on car windshields. Trying to use wipers on a dew-coated windshield can cause streaking and reduce visibility.
Laying an absorbent towel on the windshield at night causes the dew to soak into the towel instead of beading up on the glass. This prevents messy buildup and makes it faster to clear the windshield later on.
As a General Protective Layer
Towels placed on windshields also act as a physical barrier against various environmental hazards. They guard against dust, tree sap, bird droppings, and other debris. Towels also prevent scratches from branches or cleaning tools scraping against the glass.
Using extra towels for this sacrificial layer helps maintain the clarity and integrity of the windshield glass. It saves the effort of having to clean or replace the glass due to damage.
When Getting Work Done on a Vehicle
Mechanics often cover a vehicle’s windshield with a towel when servicing the engine compartment. This protects the glass from spilled fluids and debris while working on the car.
It also blocks the sun from heating up the interior while the car sits idle with its hood up. The towel takes on the abuse so the windshield stays clean and scratch-free.
As a Visual Cue the Car is Occupied
Displaying a towel on the windshield can signal to parking enforcement and others that a car is currently occupied. For example, putting a towel in the windshield may deter parking officials from ticketing the car for exceeding time limits.
Some people also hope this visual cue deters criminals from targeting the vehicle. The towel implies someone is currently using the car and may return at any moment.
To Save Money on Formal Sunshades
Purchasing a fitted windshield sunshade can cost $20 or more. Many car owners opt to use an old towel instead of buying a specialty sunshade. Towels are free, reusable, and serve most of the same functions.
Using a towel as a disposable cover can also avoid having to clean a reusable sunshade after it gets dirty. When the towel gets too soiled, it can simply be discarded or repurposed.
Out of Habit or Tradition
Some people cover their parked cars out of habit, even when conditions don’t necessarily warrant it. They may have always seen their parents or grandparents use towels this way while growing up.
The practice then continues out of tradition or habit. People often say this ritual reminds them of loved ones who used towels on their cars years ago.
Other Improvised Windshield Covers
While towels are the most common improvised windshield cover, some people use other materials:
- Cardboard – Can provide insulation against heat and cold.
- Newspapers – Layered paper absorbs condensation and blocks sun.
- Reflective space blankets – More effective than towels at reflecting sunlight.
- Pillowcases or sheets – Readily available in many households.
- Aluminum foil – A very reflective material that seals out light.
- Tinted plastic film – Clings to glass and reduces glare.
Almost any item that can cover the expanse of the windshield can serve as a temporary sunshade or protector. But towels remain the cover of choice for most vehicle owners.
Potential Disadvantages of Towels on Windshields
While using a towel on the windshield has its benefits, there are also some potential drawbacks:
- Can blow away in strong winds
- Less effective sun protection compared to fitted shades
- May scratch paint if flapping against the hood
- Can collect dirt and dampness if left for long periods
- A soaked towel can mildew and leave musty smells
- Makes the car look unattended
- Indicates owners are not using the car regularly
Proper precautions can help avoid most of these problems. But fitted sunshades are inherently more secure and effective.
Are There Laws Against Towels on Windshields?
There are no specific laws against using towels or other items to cover windshields. As long as the materials are secure and do not obstruct the driver’s vision, it is legal throughout the United States.
However, some state or city codes prohibit leaving cars continuously parked on public streets or leaving them unattended for over 72 hours. A towel on the windshield could cause officials to think the unused car has been abandoned.
Check with local parking enforcement before leaving towels or bags on a car parked long-term on the street. Covered windshields on cars parked in legal private driveways are generally not an issue.
How to Choose a Towel as Windshield Cover
For best performance, choose towels with properties ideal for windshield coverage:
- Absorbent material – Terry cloth or microfiber absorb moisture well.
- Compact size – Fitted towels contour better and resist flapping.
- Dark colors – Absorb more UV rays than light colors.
- Thick pile – Insulates against temperature extremes.
- Water repellent – Sheds rain and irrigation water.
- Durable – Withstands long-term outdoor exposure.
Avoid towels made with delicate fabrics like linen or raw silk. Prioritize functionality over appearance when selecting a windshield cover towel.
Alternative Methods to Protect Interior
If you choose not to use towels on the windshield, there are a few other options to protect your car’s interior:
- Use tight-fitting sunshades designed specifically for windshields.
- Install window tints to block UV light.
- Use a windshield heat reflector to lower interior temperatures.
- Crack windows slightly to allow ventilation.
- Park in a covered garage or under shade.
- Use a car cover to shield the entire exterior.
But for a quick, inexpensive way to shade your car, it’s hard to beat throwing an old towel over the windshield.
Conclusion
Placing towels on windshields is an age-old tradition that persists today for a variety of good reasons. Towels shade interiors, insulate against extreme temps, protect from UV rays, absorb dew, and deter prying eyes. For most car owners, the benefits of using this improvised auto cover outweigh any minor hassles.
So don’t be surprised to see those towels draped casually on cars at the beach, park, concerts, and other sunny locales. It’s not a silly old habit – but a classic trick still useful today!
