A vehicle that has been severely hit is an accident vehicle if it meets one of the following conditions: First, whether there are any impact marks on the girder of the whole vehicle (even after repair), the inspection method should be that the whole chassis is almost the same dirty, no part is particularly clean, and the girder is straight; Second, whether the water tank bracket has collision damage (even after repair or replacement); The third is whether the rear fender of the car body has been cut and replaced. The joint between fender and carriage and car body should be smooth, and the welding spot on it should be slightly round and concave. If the solder joint bulges, it is a trace of re-welding.