My wife and I were out on OBX in early June, before we bought our CP 2008 Touareg. We stayed in Corolla and took one of those group SUV trips up there. The SUV's used where much bigger than the Treg with bigger offroad tires and higher suspensions (unless you have air suspension), alongside your normal Jeep Wranglers and such. (There were plenty of other smaller SUVs crawling the beach too - think RAV4 etc. but I have to hope they stuck to just the immediate beach and had 4x4 of some sort.)
That said, couple things that come to mind - the Touareg manual actually says not to let air out for driving on sand. See your Driving Your Touareg manual. Now in real life this may or may not prove useful - leave it up to those with actual time offread and on sand.
Also if anyone has ever heard of Pismo Beach in California, they let you drive any car right out on the sand. A few years ago I did that with a rent-a-car and had no touble. (I would not have if others were not doing it also.) But yes stay on the more solid sand. No dune buggying.
Back to OBX, those big SUV trips also go off the main beach and up over the front dune (which is pretty solid) and deeper into the wild area which is full of sandy trail roads, enough water pools to be careful about, and lots of houses/properties. The big group SUV tour driver (was a Chevy or Ford or something can't remember) went through several pretty deep water pools on a sandy road on the way back to the beach area. I don't know if those pools where greater than 19 inches (maximum depth for a non-air suspension Touareg) and you'd really want off-road tires I imagine. Might want to stick to the beach, and unless you have a set of offroad tires and air suspension, is my gut feeling.