Ticket for using Dealer plate

Can one of you guys clear this up for me since it's the weekend and I can't talk to the DMV.


To start off, I own a car dealership and will sometimes drive cars with dealer plates back and forth to work. I needed to put miles on one of my cars to pass inspection so I decided to drive it downtown to meet a few friends for food last night as driving in traffic areas greatly speeds up that drive cycle process, didn't think anything of it. A police pulled out behind me of the parking lot after I finished eating and promptly pulled me over for " misuse of dealer plate" . I had my registration, proper tags on and everything. I cooperated and answered questions. I asked him what law I was breaking exactly and he said that I should only be doing this during business hours. I've read the DMV illegal uses of dealer plates and this is nowhere on there, if it was then I wouldn't be using the plate late at night. I asked the cop multiple times what law I was breaking and I don't think he really gave me a clear answer so I hope one of you can help so I can avoid this next time, or maybe there's a second set of rules that are different than the following.

http://reports.oah.state.nc.us/ncac/...3d%20.0224.pdf