I live in NC as well, and some of the vanity plate options I had written down included:
MSP-2746
and
MSP 2746
The woman behind the counter didn't even check the computer before telling me I couldn't have one of those. Apparently, if it's too close to one of their randomly issued plates, you can't have it, period.
BTW, the following are taken:
SLOWPOKE
SLO POKE
SLO-POKE
BLUEGLUE
Keep in mind, if you go in there with a list of 10-15 plates, all written down in order from most to least favorite, you'll end up getting stuck with the one that you threw on there at the last minute thinking, "I doubt I'll need it, but I *guess* it's better than no vanity plate at all..."