There are a couple of varieties of 'redneck,' the 'good ole boys' (definitely not cosmopolitan, but good people), and trailer trash. Trailer trash are what perhaps most think of when the term redneck is used... and most of what Red Dawn said is true about them (of course, you forgot that they spend most of their waking hours in AOHell chat rooms and watching Jerry Springer). Trailer trash certainly aren't a simply Southern phenomenon, but then again, southerners haven't come up with a good name for yankees that meet the definition.... calling someone from Michigan or Oregon a "redneck" just sounds kinda silly.
And i don't think this necessarily applies to you Starlitt, but that some folks get a cold reception down south might have something to do with the fact that they're driving a Volvo with New York or Massachussetts plates, and with bumper stickers that support gun control, gay marriage, and "Hillary for President 2004!" How hard is it attempt some camoflague, and rent a 4x4 during your visit, and not ask for Perrier and how the foie gras is prepared when you're at a truck stop or Waffle House? Act interested in things revelant to your audience (even if you could care less), and ask "how do you folks make your ribs taste so good down here? We can't even get them up North" or "how do you think State will do against Tech this year?" (tailor to the locality). I've never had politeness on my part not returned with politeness when i've been down south.