A vehicle does not need to have structural damage to be a total loss, a vehicle is only ever a total loss when repair costs exceed the market value. For example, older cars tend to get written off with minor damage because even low repair costs can exceed the value of an older car. Always get any previous total loss vehicle inspected as it may have had low level water ingress. Even though Cat N cars have sustained non-structural damage, the accident damage may not have been repaired (or it could have been repaired poorly). I would want a substantial discount if purchasing any previous total loss vehicle.