Respect
The Southern drawl in language is generally charming to most outsiders. In most cases, mutual respect is expected and southern hospitality is a staple of the area. This is expressed in a number of ways: holding doors open for strangers, not honking a car horn unless necessary, and keeping one's voice down when in a crowded room.
As is common in other parts of the South, North Carolinians typically take offense at being stereotyped as "hicks" or "rednecks". While some rural residents might apply such labels to themselves as a matter of humor, it is not expected that outsiders will follow suit (this is similar to the double-standard common in American race relations, where a word may be taken as a complement or a slur depending upon the social status of the speaker). It is very strongly advised that visitors treat the locals with the same respect that you'd afford to any other group of people, and not attempt to make a joke out of age-old class discrimination.
