S.C. Code Ann. § 56-5-6420: Transportation of children in the front seat of a motor vehicle.

If a motor vehicle lacks a rear passenger seat or if all of its rear seating positions are occupied by children under eight years of age, a child under eight years of age may be transported in the front seat of the motor vehicle if the child is secured properly in an appropriate child passenger safety restraint system or belt-positioning booster seat as described in Section 56-5-6410(1), (2), or (3).