The Germiest Areas In Our Cars Revealed In New Study

car germs vehicle bacteria automobile viruses

Many of us have never given the interior of our cars a second thought. But did you know that there are areas of the cabin accumulating germs and bacteria before our very eyes? 

ATS Euromaster and the Biochemical Engineering department at UCL teamed up to find out exactly what types of bacteria are in play, and where they’re located. This is especially important in the age of deadly pathogens like MRSA and Covid-19.

Eleven cars were under inspection at the ATS garage in Brixton Hill, with Professor John Ward leading the investigation. Here were the results of bacteria, viruses, mold, and mildew found in automobiles. 

The Germiest Areas On A Car Revealed 

1. Cup Holder 

In first place for bacteria growth is the cup holder. Professor Ward says: “The cup holder – it’s exactly that… a holder with a shape designed to hold and retain the cup… as well as any other small bits of debris. With some little bits of liquid, this provides quite a good little environmental niche for bacteria to be trapped and grow.” 

2. Dashboard Buttons 

Dashboard buttons are regular touchpoints on a vehicle, which perhaps don’t get cleaned as often as they should. Just think of how often you and your kids touch those buttons!

3. Seat Belt Catch 

The seat belt catch is touched at least twice every car journey. The gap where the seatbelt plugs into provides an area for dirt, like crumbs and flakes of skin, to accumulate. 

4. Steering Wheel 

Following this was the steering wheel. The wheel was swabbed at the ten and two hand position - the areas receiving the most contact from drivers. 

5. Door Handle 

This smoother and more exposed surface preserves less bacteria compared to the cup holder and seat belt catch - areas which can collect and store germs more easily. 

6. Gear Stick 

Despite this being a frequent touch point, the gear stick has a small surface area. Your car's gear shifter also a smooth and shiny surface, which helps keep bacteria at bay. 

What Bacteria Were Found And Are They Dangerous? 

Staphylococcus Epidermidis

Staphylococci are bacteria of the skin, also found less commonly in the nasal passage. They can be harmful to people with weaker immune systems if ingested. 

Staphylococcus Aureus 

The most dangerous of the Staphylococcal bacteria; it can cause skin infections, as well as pneumonia and other types of infection. The staphylococcus aureus bacteria live on the skin’s surface and cause infection if they get into the skin. 


These are bacteria found in the mouth and open wounds and are known to cause infection. They can attach to other bacteria forming larger colonies and cause illness. 

Micrococcus Luteus 

Micrococcus luteus is bacteria found on the skin. It is not harmful to humans. 


A type of bacteria found in soil and water. Generally, it is harmless to people with strong immune systems. Those with weaker immune systems and lungs, however, are more at risk of infection. 

Bacillus Mycoides And Bacillus Subtilis

Commonly found in soil, as well as the gastrointestinal tract of humans. These are usually unharmful bacteria for most people, though they have been known to cause food poisoning. 

How These Results Were Obtained 

Eleven cars belonging to members of the public at ATS Euromaster in Brixton Hill were chosen; these were swabbed for bacteria. The swabs were placed in agar plates and incubated at 30 degrees. Photographs were taken after four days and again after three days. 

The bacteria hotspots were the cup holders and seat belt catches. These creviced areas retain large amounts of bacteria, some of which can cause illness. The shiny touch points with smaller surface areas – namely the gear stick and door handle – picked up the fewest bacteria. 

The important factor to take away from this study is to clean your car regularly with chemicals that will kill germs. Don’t be afraid to get inside those smaller areas which store bacteria - and be sure to give everywhere a thorough clean. Keeping your car clean also helps prevent buildup of viruses, mildew, mold, bugs, and even rodents. As recommended by Professor Ward, “clean your car as you would your home.” 

Discover all the bacterial findings – and the methodology in full – by taking a look at the ATS Germs in Cars campaign.

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