Someone/something that is so extremely sketch that it is beyond the classification of a red flag.
Originates from the railroad practice of using blue flags on trains to signify to people that a locomotive and anything connected to it should not and cannot be touched by anyone other than it's crew.
Guy 1: "Bro, I just started reading Burrows and Mark is so fucking hot."
Guy 2: "Don't bother, he's a blue flag."
A phenomenon in which otherwise normal people become extremely agitated and hostile when driving. This disorder is named after the main character in the 1950 Disney animated film "Motor Mania".
"Hey? Did you read the news? Someone got shot in a road rage incident because they cut someone off."
"Another case of Mr.Wheeler Syndrome I'm afraid."