From the AG's website:
"If the weapon is concealed near, in close proximity to, or within the convenient control and access of an occupant, which would allow him/her to use the weapon quickly, then a fair probability exists that the occupant is in violation of the law. Therefore, care must be exercised by any occupant of any vehicle to ensure that weapons are securely locked away in as remote an area as possible, in relation to the passenger compartment of the vehicle. It is important to emphasize that these prohibitions apply to passengers, as well as drivers of any vehicle."
If your glove box locks he'd probably be OK, since it wouldn't be "within the convenient control" or "allow him/her to use the weapon quickly". But if not I guarantee you there's a cop somewhere in NC that'll arrest him for it. I don't have any case law, or experience with your particular situation, but it's definitely a possibility. It's most likely one of those situations where the charges would be later dismissed, after a lot of lost time and expense to your passenger, if he's doing nothing wrong at the time. "Fair probability" would seem to me to mean it's a bad bet in Vegas!
RE: Link Removed, secion "D Transporting Weapons"