Mighty mopars tag

I could be mistaken, but I believe what you will find is the ones with the "S" were dealer specific tags, like this:
MIGHTY MOPARS.jpg

Century Dodge in Macon used to have them on the performance cars back in the day. I had one or two YEARS ago. I've never seen one with the "S" that didn't have a dealer name at the bottom.....but that doesn't mean anything.