The better oil perfume is shaking violently, will slowly produce some big bubbles, and perfume constantly have a fine small bubble gradually from the bottom up, and fake perfume because it contains too much alcohol so that the liquid is diluted, in the shaking quickly produced many small bubbles and a lot of water, perfume a strong sense of the liquid. The aroma retains a long time, but the low quality perfume, which is made with alcohol, loses its fragrance in two or three hours. The perfume in the car is not so strong that it only mixes with musty odor. Therefore, the best choice in summer is neutral, lighter flavor of perfume. Long-term motorists can consider the choice of refreshing brain mint flavor.