The fragrance diffuser from the Range of Accessories available for the Fiat 500 is an electronic multi-fragrance device for the controlled diffusion of perfume inside the vehicle. The idea behind this innovation is the opportunity to offer the customer a multisensorial vision of the interior that beyond visual and tactile aspects also includes the sense of smell, enabling the vehicle interior to be highly personalised. The project has entailed the development of a collection of three perfumes as well as the design of the device itself, which allows the customer to select a fragrance and change it, if desired, during the trip, regulating the intensity of delivery so that the perfume can always be perceived but it is not irritating, and completely stopping diffusion when the device is switched off. CRF contributed mainly to the development of the delivery control system and its validation, specifically as regards electric/electronic gauging and assessing olfactory quality inside the vehicle.