10ml Car Diffuser Comes With Air Vent Clip Duration 15–20 Days Wooden Lid Diffuser Cap Black Ice is the sharpest scent in our car range — cool, crisp, and slightly masculine, with none of the sweetness of the florals. It is the one to choose if you want the car to smell clean rather than fragranced, and the closest thing we make to a classic barbershop scent. The wooden lid absorbs the oil and releases it slowly, so the fragrance holds steady for two to three weeks rather than fading after a few days. How to Use Unscrew the cap and remove the seal. Replace the wooden lid and tip the bottle gently to saturate it. Hang from the mirror or fit the vent clip — keep it out of direct airflow so the scent releases gradually rather than all at once. Re-saturate the lid when the scent fades. Avoid over-tipping, which can cause leaks. Keep upright when not in use. Wipe spills promptly — fragrance oil can mark interior trim.