A driver in downtown St. Louis was shot because he rolled down his window to hock a loogie in traffic — infuriating others on the road and sparking an argument, according to a new report.

The mucusy motorist, 27, had stopped in traffic to spit at Washington Avenue and 14th Street around 1:20 a.m. Saturday — apparently enraging two men in another car, who began yelling at him, police told the St. Louis Post-Dispatch.

An argument ensued and that’s when one of the men pulled a gun and fired a shot in the air.

The spitting driver tried to flee the area — but encountered the pair again a few blocks west. He heard a gunshot and realized he’d been shot after feeling pain in his arm.

A woman who was in his car wasn’t hurt. The victim drove himself to the hospital but his condition wasn’t known.

Cops didn’t have a description of the suspects or their car.