Many private car owners like to wash the car in the sun, thinking that the water on the car body can be dried quickly after washing. In fact, it is wrong. When washing the car in the sun, the convex lens effect formed by the water will cause local high temperature on the top layer of the car paint. Phenomenon, over time, the car paint will lose its luster. If waxing at this time, it is easy to cause uneven color of the car body. Therefore, car washing and waxing are best carried out under sheltered conditions. If there is no guarantee, it is best to choose to carry out in the morning and evening on a cloudy or sunny day. When the weather temperature rises, the dust increases, the body is easy to get dirty, and the frequency of car washing by car owners also begins to rise. Many car owners also hope to wash their cars thoroughly like they are bathing themselves. However, it should be noted here that the appearance of the car air conditioner must be kept dry. If the car air conditioner is accidentally wet, it will affect the life of the car air conditioner. There are many fasteners connected by bolts and nuts on the automobile, and it should be ensured that they have sufficient pre-tightening force, but they should not be over-tightened. Deformation; on the other hand, the bolt will be stretched and permanently deformed, and the preload force will decrease instead, and even cause the phenomenon of slipping or breaking. Many people are used to waxing the body in a circle, which is not the correct way. The correct waxing method is a straight line, alternating horizontal and vertical lines, and then the last one in the direction of the rainwater flow, so as to achieve the effect of reducing the concentric halo on the paint surface.