My wife had a large Ichthys emblem (think Jesus fish) on the back of her car and on a 16 hour road trip she got very upset when I utilized my horn and my "Single Finger Driver Annoyance Signal" after nearly getting creamed on the highway in a construction zone in Massachusetts. Why'd she get upset? Because she (rightly) felt that anyone who would see me behaving poorly on the highway would associate it with Christians in general because we were professing our faith with a decal and a emblem on our car. The same with displaying the S&C on a car. If you're driving like a maniac or trying to emulate Dale Jr. with your car decked out with every imaginable FM symbol, how does that look to the rest of the world? Think about it when you see someone with a out of state plate driving like a moron... the first thing you probably think is, "Wow, drivers from that state must all be morons."
... and my reaction would likely be to write a citation. That's blatantly asking for special treatment in my book, and ranks right up there with any brother cop who has his badge pressed up against the window when I approach the car... not a good way to start off the encounter. Also think of this: not all cops are Masons! What would a profane cop think of that? "Sh*t, do these Freemason people think they have a get out of jail free card?" Not the best way to be representing the Craft.
Now, now!