A BATTERED OLD Lincoln Town Car - one with a flat tire and a tarp instead of a window - held a nightmare in its back seat.

The car sat undisturbed on Park Avenue near Cumberland Street in North Philly until shortly after 7 last night, when someone called 9-1-1 and reported seeing a body inside.

Patrol cops who arrived on the block made the grim confirmation: a 15-year-old boy was dead in the back seat, with a gunshot wound to his head, said police Chief Inspector Scott Small.

The teen's name was not released, but Small said he was identified by relatives who were at the crime scene as an Upper Darby resident who was reported missing on Dec. 9.

Homicide detectives were interviewing the victim's family last night. Investigators were also questioning the owner of the 1998 Lincoln, which Small said looked abandoned, based on its sorry appearance.

Little else was known about the incident - there were no suspects or motives, or sense of what could have led the teen to end up in a car in North Philly.

Small said investigators might learn more from private surveillance cameras affixed to local houses, and from a city-owned surveillance on nearby York Street.

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