according to Wikipedia, "In Georgia, North Carolina, Alabama, Maryland, Mississippi, South Carolina, Tennessee, Virginia and Louisiana vehicle owners can request a license plate from the state featuring the Sons of Confederate Veterans logo, which incorporates the square Confederate Battle
[WS:] The only "custom" license plates that you can request in Maryland are "Treasure the Chesapeake" and "Our farms our future"
https://secure.marylandmva.com/eMVAServices/VRR/dept.asp
While I share your feelings about the confederate flag and the south in general, I am also aware that the confederate flag symbolizes many things to the southerners, not necessarily slavery.
Wojtek