New car has been used for some time, some owners will find some small jitter, but do not know what is wrong. "Body jitter" is a signal that tells the owner of the car that something has gone wrong. Professionals say that body jitter looks like a trivial matter. If you don't pay attention to testing, it will cause big trouble. Then, what is the problem of body jitter? How can the owner of the car judge and solve it?