They must have 2 rear facing mirrors, one of which must be on the left side. Thats federal vehicle code. Ive owned cars that were never equipped with seat-belts and been thru the court system for years with new cops enforcing new laws on grandfathered vehicles. However, While the court fights were going on I read alot of vehicle codes. From federal down to my local town.
I am very happy to figure this out as soon as I have his local town so I can read the local ordinance. SC state law is the same as federal law.