A man urinating on a parked car in Manhattan slashed the throat of a passerby who told him to stop, leaving the victim clinging to life, police said Monday. The 66-year-old victim and two other passersby complained when they saw the stranger urinating on a car parked on E. 14th St. near First Ave. in the East Village about 5:05 p.m. Sunday, cops said. That sparked an argument, during which the victim was slashed in the neck, causing what police described as a “severe laceration.”Medics rushed the victim to Mount Sinai Beth Israel in critical condition. On Monday, cops released surveillance images of the suspect and asked the public’s help identifying him and tracking him down. Anyone with information is asked to call Crime Stoppers at (800) 577-TIPS.