What Is a Car Diffuser? A car diffuser bottle is a perfect way to enhance car interiors in terms of the atmosphere and smell inside. A car diffuser is a car accessory that's more eco-friendly than traditional car freshener cards. How it works? The wooden diffusing lid expands when infused with the oil from the glass bottle using heat from the sun and your car. Therefore, the diffusers work best with heat and in warm conditions. As you drive your vehicle, the diffuser will move, giving off an occasional aroma. Directions for use: Unscrew the lid, remove the bottle stopper and replace the lid. Turn bottle over and hold in this position for 1-3 seconds. Hang where desired. Whenever you feel the scent is no longer that strong as you’d like, simply turn bottle over again to soak the inside of the lid. With this order you get diffuser filled with scented oil Volume: 8ml Warning: Avoid any liquid coming into contact with the dashboard or upholstery as fragrance oil reacts with plastic, laquer and polish and damage will occur. If this does occur wash immediately with soap and warm water to avoid damage. It is not corrosive to skin but if in contact with skin or eyes wash immediately with soap and warm water and seek medical advice if necessary. Do not let children or pets play with the product.