Sale or exchange of used vehicle without certificate of safety. No person engaged in the business of buying, selling or exchanging motor vehicles shall sell, transfer or exchange any used second division vehicle or medical transport vehicle unless it has been tested and a currently valid certificate of safety has been issued therefor: Provided, that such person engaged in the business of buying, selling or exchanging motor vehicles may sell, transfer or exchange any used second division vehicle or medical transport vehicle without a valid certificate of safety if the sale, transfer or exchange is for the purpose of restoring or repairing such vehicle to a condition in which it can pass the test for a certificate of safety, or for the purpose of junking. Provided, however, that the used second division vehicle or medical transport vehicle is not moved under its own power to the location in which it will be restored, repaired or junked.