The first fire was reported near South 30th Street and Hoffman Boulevard at about 11 p.m., Richmond police said.
The vehicle was a 2002 Dodge that had been reported stolen, and the fire started in the front passenger seat, Banks said.
The second blaze was reported across town at about 11:30 p.m. in the area of Via Verdi and Mozart Drive, near El Sobrante, police said.
When firefighters arrived, they found a flatbed tow truck in flames.
Banks said the second fire was still under investigation this afternoon, but investigators have ruled out any possible connection between the two fires.
Investigators do not believe either fire is connected to a series of car arson fires reported in west Contra Costa County last November, Banks said.
"Unfortunately we get quite a few vehicle fires in Richmond every year," Banks said.