If you think the air fresheners for cars are too overpowering, but would like to add a subtle fragrance try putting a few drops of your favorite essential oil fragrance to a wooden spring-clip clothespin. Attach this to the air vent. This natural, calming aroma will follow you while you drive. Add a few more drops to the clothespin as the scent starts to fade. No chemical plus one bottle of essential oil will last much, much longer than a store-bought freshener.