A citizen not otherwise prohibited can legally carry a loaded gun in his car's glovebox, console or trunk that is shut not locked.
SECTION 16-23-20. Unlawful carrying of handgun; exceptions. [SC ST SEC 16-23-20]
It is unlawful for anyone to carry about the person any handgun, whether concealed or not, except as follows, unless otherwise specifically prohibited by law:
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(9) a person in a vehicle if the handgun is:
(a) secured in a closed glove compartment, closed console, closed trunk, or in a closed container secured by an integral fastener and transported in the luggage compartment of the vehicle; however, this item is not violated if the glove compartment, console, or trunk is opened in the presence of a law enforcement officer for the sole purpose of retrieving a driver's license, registration, or proof of insurance; or
(b) concealed on or about his person, and he has a valid concealed weapons permit pursuant to the provisions of Article 4, Chapter 31, Title 23;