It’s time to rethink air freshener for cars. Forget about scented pine trees and too-sweet vanilla. Diptyque, which is known for its heady and complex scents, also offers a car diffuser. About the same size as a deck of cards, it clips onto the ventilation grills, and the fragrance intensity can be adjusted. Available scents include Baies, Ambre, Figuier, Roses, Orange Blossom, Ginger and 34.