Steve has very kindly let me know that I did not see a terrorist symbol but instead a stylized version of the South Carolina state flag.
And just for the record, I may be a Yankee with "odd notions" but I live too close to Ground Zero for comfort.
As a child, I used to go with my father to a park where we could look across the Hudson River and see the World Trade Center being built. It was to be the tallest building in the world and he wanted us to see it happen.
At the very tollbooth we drove through on Monday (exit 12 of the NJ Turnpike) we could see the Twin Towers as we waited to pay for the privilege of driving on that particular highway (but that's a rant for another day).
I'm a North Jersey native, and many of the villains of 9/11 roamed my hometown.
I am glad that it was a South Carolina sticker on that car, but I don't think I will ever really breathe easy again.