At least where I live, the cops have better things to do than pull people over for stickers, especially since “he had a sticker” isn’t in any way probable cause for a stop, and therefor any evidence gathered as a result of the sticker stop would not be admissible.

Somebody else posted about cops pulling a lady over for what they thought was a pot leaf sticker. Let’s say she did have pot in her car in plain view, and was arrested. That initial action that would lead to the arrest would be invalid, and that case would be thrown out, because having a non hazardous sticker on your car is not a crime, because it’s free speech. Most cops know this, and don’t want to get written up by their sergeant for making bad stops when so many other opportunities for good stops exist.

Seriously, if a cop wants to pull you over, they don’t need a sticker to do it. They’ll wait for you to inevitably break a traffic law, and then they’ll pull you over.

Note how I said that some stickers will make cops find a reason to pull you over...