An officer sent to the 2200 block of Tidelands Avenue near Bay Marina Drive spotted the body in the fire-engulfed vehicle shortly before 10 p.m. Sunday, a National City police dispatcher said.
It was not immediately clear if the body was that of a man or a woman, or whether that person was killed in the fire.
Meanwhile, Chula Vista firefighters found the body of a man when they put out a brush fire in a ravine behind a retail center, according to a lieutenant.
The fire was reported about 9:05 p.m. Sunday in the 500 block of C Street, Chula Vista police Lt. Kenny Heinz said.
The blaze broke out in a ravine frequently used as a homeless encampment, Heinz said. The body was found at the bottom of the ravine.
Chula Vista homicide investigators, arson investigators and crime lab personnel were summoned to the scene to determine if the fire and death were an accident or intentional, he said.