Uncertain about "fox tag", but to "roll coal" is to intentionally bork up the emissions of your car, leaving a black cloud of smoke and stench behind one's car.

Uncertain about "fox tag", but to "roll coal" is to intentionally bork up the emissions of your car, leaving a black cloud of smoke and stench behind one's car. https://en.wikipedia.org/wiki/Rolling_coal https://en.wikipedia.org/wiki/Rolling_coal