She thought it belonged to her ex-boyfriend, detectives said.
Carmen Chamblee, 19, now faces charges of second-degree arson, according to the Clearwater Police Department. She was arrested Saturday morning by the Pinellas County Sheriff's Office, just south of Clearwater's city limits.
Chamblee started the blaze inside the white four-door vehicle's trunk, police said, in the 1100 block of Blanche B. Littlejohn Trail on Aug. 28.
Witnesses told investigators she left the scene on a bicycle. A couple of days later, police released video of a woman with a purse slung over her arm feeding the flames. Police said they identified her as Chamblee.
She told police she thought the car belong to a former boyfriend.