How to safely leave your car in the sun: tips for protecting the bodywork and interior

In summer, a car suffers not only while driving, but also when parked. While the driver relaxes on the beach or works in the office, the bodywork heats up to 70 °C, the plastic in the cabin becomes softer, and the air inside turns into a veritable sauna. A single hot day rarely leads to serious consequences, but if the car stands for weeks under the scorching sun, problems begin to accumulate. The good news is that most of them can be avoided.

Why heat is dangerous for a car

The main enemy is not the high air temperature, but direct sunlight. In the sun, the car body heats up far more than the surrounding environment, and the paintwork constantly experiences temperature fluctuations.

The following can suffer from heat:

• Paintwork
• Plastic interior components
• Trim made from natural and artificial leather
• The infotainment screen
• The battery
• Rubber seals

If the bodywork has not been protected with wax or a ceramic coating for some time, ultraviolet light gradually reduces the intensity of the colour. This is particularly noticeable on red, blue and black cars. The sun does not pick favourites – it is equally merciless to a budget saloon and an expensive SUV.

How to protect the cabin from the blazing sun

The car cabin heats up faster than the bodywork. Within an hour, the temperature under the windscreen can be significantly higher than the air temperature outside.

To reduce the heat build-up, it is worth following a few simple rules:

• Use a sunshield on the windscreen
• Park in the shade wherever possible
• Slightly open the windows if it is safe to do so
• Regularly treat plastic and leather with protective products
• Do not leave electronic devices on the dashboard

Even an ordinary sunshade can noticeably reduce the temperature of the dashboard and steering wheel.

How to leave your car for a holiday period

If the car will not be used for several weeks, it is best to prepare it for storage in advance.

Before a long period of standing, it is recommended to:

• Thoroughly wash the bodywork
• Remove traces of bitumen, resin and insects
• Apply a protective wax
• Check the tyre pressures
• Remove food, drinks and power banks from the cabin

If possible, it is better to use a breathable protective cover. However, covering a dirty car with a heavy tarpaulin is not advisable: underneath it, dust turns into an abrasive which, at the slightest breeze, begins polishing the lacquer in a rather peculiar way.

Why the battery is under strain in summer

Many people believe that the battery only discharges in winter. In practice, heat also shortens its lifespan.

High temperatures accelerate the chemical processes inside the battery, increase self-discharge and promote evaporation of the electrolyte. If the car stands idle for a long time while the security system remains on standby, the charge gradually drops.

This is especially noticeable on cars with alarms fitted with tilt and impact sensors. In summer, the body expands and contracts more, and there are more vibrations from thunderstorms, wind and passing traffic. The electronics wake up more often, periodically activating the sensors and consuming energy. It is a curious paradox: in winter the battery spends its energy on cold-starting the engine, while in summer it spends it on patiently waiting for its owner.

What you should never leave in the car

High temperatures are dangerous not only for the car itself, but also for the items inside it.

In hot weather, it is best to take the following out of the cabin and boot:

• Gas canisters
• Aerosol cans
• Lighters
• Lithium-ion batteries
• Medicines
• Plastic bottles of fizzy drinks

Under strong heating, the pressure inside aerosols and lighters rises sharply. At best, they will lose their seal; at worst, they may rupture, damaging the car's interior. That kind of firework display is certainly not on the list of summer entertainment.

Simple habits that will preserve your car

It is impossible to protect a car completely from the heat, but it is entirely feasible to significantly reduce its effects.

It is enough to follow a few rules:

• Choose shaded parking spots
• Use sunshields
• Wash the bodywork regularly and renew the protective coating
• Do not store hazardous items in the car
• Monitor the battery condition during long periods of standing

A few minutes of preparation cost far less than restoring a faded interior, replacing a battery or respraying the bodywork. The summer sun does not forgive mistakes – but it is all too happy to reward careless owners with them.