Police are conducting a homicide investigation, after the body of a woman in her 50s was found wrapped in a carpet in the woman's driveway last night on Punahou Street.  The woman's ex-husband made the discovery at about 7 p.m. He alerted a security guard working at a building next door and police were called.  Homicide detectives say the woman's 2013 Mercedes Benz sedan with paper plates was missing.  They found the car later in the evening at Kapiolani Park.  Criminal Investigation Division Major Richard Robinson says there are injuries on the woman that indicate it's a homicide. No arrests have been made.