First of all, he isn't going to be able to read a damn thing speeding by him at a 90 degree angle. Second of all, the author does not mention one instance where this is or has been the case. A federal report discussing possible affiliations is not sinister, it's common sense.
Now if the FBI Bulletin said, "if the car has an NRA sticker, it's a nut" that's one thing. But it didn't, and no amount of imagining it makes it so.
Your bumper stickers can indeed determine if you are pulled over or if you receive a ticket. Police have much more descretion than you perhaps imagine.
I get pulled over 2 or three times a year for minor offences. I rarely receive a ticket though. My "Don't Drink and Drive" and my "Texas State Troopers Association" bumper stickers label me as a law and order type. LOL..if they only knew;-)
It works better than "No Fear" or "Party Mobile" bumper stickers. Getting a "Legalize Pot" bumper sticker is like asking the police to pull you over. Don't believe me? Get one.