A person at a neighboring business called in the fire shortly before 7 a.m., according to the incident report. Firefighters said that heavy smoke was pouring from the rear of the one-story, wood-frame building when they arrived.
About 30 firefighters brought the blaze under control in a little more than 15 minutes.
Incendiary material or device caused the fire, the report states.
About 10 percent of the building was damaged. Knox Auto Sales is listed at the address.
Raleigh police and the City/County Bureau of Identification responded to the fire.
The fire caused some congestion along Capital Boulevard.