The body was found after a report of a car fire in the 5500 block of Paschall Avenue in Southwest Philadelphia around 3:30 a.m. Monday.
Neighbors were awakened by the sound of the Nissan Maxima's horn, somehow activated by the fire.
The victim was found in the back seat with his hands tied behind him and duct tape around his neck, Philadelphia Police Capt. James Clark told Action News.
Investigators told Action News that two men were seen getting out of the car seconds before it burst into flames.
The dead man's remains were burnt beyond recognition and authorities are still attempting to identify him.
Police are waiting for the medical examiner to determine an exact cause of death. However, they say there were signs of obvious trauma to the victim's head.
"Probably he was killed before and he was taken there and the car was torched," Clark said.
Investigators say they are confident they'll be able to identify him despite the fire. That hasn't been the case with two other similar incidents over the past nine months.
In January, a man's body was found in a burning van on the 3300 block of North19th Street in Tioga-Nicetown.
In June, a body was found in a burning car in Pennypack Park near the 2300 block of Woodward St.
Those victims have not yet been identified.
In this latest case, police say they have retrieved video surveillance from cameras on a building near the scene.
Anyone with information is asked to contact Philadelphia Police at 215-686-TIPS (8477), text a tip to PPD TIP (773847) or through PhillyPolice.com.