welcome to the forum sauer...
to answer your initial query...more or less. there are no specific statutes on the books saying you can't or how to OC, while the statutes do cover how you can CC. now there are areas which are prohibited carry of ANY/ALL firearms ~ educational, courthouses, state buildings, federal property, after consumption of alcohol or use of a controlled substance etc, and areas which specifically prohibit CC'g, LE/correction facilities, offices of state/federal, posted property (some specifically state no CC though). does that mean you can OC...eh, not sure i wish to be a test case.
you will find a flyer at the beginning of this thread which will provide you some information about OC. many NC OC'rs carry it with them to give to ppl when they engage them in conversation about their OC firearm..
here is the NC attorney general's firearm link...section III D is the area you need to visit first since it covers transport of firearms in vehicles...AG states there are NO Statutes covering how... bottom line either lay it on the seat or dash for 'open carry' or leave it on your side and provide the nice LE who stopped you that you have a firearm. (there are many opinions on the forum on how to handle the conversation between the nice LE and yourself so you can discern for yourself your approach)
finally, here is the link to the NC statutes if the AG's conversation didn't bore you sufficiently (search in the upper right):
again welcome and sit back and enjoy as the other nice NC folk come out and say hello.