Car Diffuser - Monoi To use the car diffuser: 1- Unscrew the cap 2- Remove the plastic at the opening 3- Screw back on (Do not overtighten) 4- Insert the two sticks 5- Place on your ventilation grille Please ensure that the scent does not escape from the diffuser to avoid damaging your vehicle's plastic. The more you use your ventilation system, the more the fragrance will dissipate. It is up to you to precisely adjust the intensity and frequency of use to diffuse the desired scent in your car's interior. Our car diffusers have an average consumption duration of 3 months.