Investigators say the 27-year-old woman was driving near Musgrave and Haines streets in the Germantown section of Philadelphia on Wednesday night.
Her father, a Philadelphia police officer, reported her missing when she did not arrive home.
Her Chrysler SUV, meanwhile, had been towed after it was discovered and believed to be abandoned.
Her body was later found in the vehicle.
Investigators have not yet released her name.
That part of Germantown experienced heavy flooding after a storm system hit our area late Wednesday night into Thursday morning.