https://www.caranddriver.com/news/a60983144/study-loud-exhaust-psychotic/

A new study by Western University in Ontario says that if you've got a car with a modified exhaust system, odds are you're a guy and probably also psychotic and sadistic. Slapping a Cherry Bomb glasspack on your Monte Carlo doesn't (necessarily) mean you're a Ted Bundy–level psycho, but the data points to a personality that enjoys inflicting unpleasantness on others. The study—catchily titled, "A desire for a loud car with a modified muffler is predicted by being a man and higher scores on psychopathy and sadism"—was commissioned by professor Julie Aitken Schermer, who heard many a loud car in London, Ontario, and wondered what kind of person would want their car exhaust to be louder than normal. She probably could have saved a lot of time by simply looking up Cadillac Escalade-V registrations.