A possible road rage incident in Newtown is under investigation.  Police received a report from an older man Wednesday evening about another driver waving a gun at him as they drove down South Main Street.  The complainant's car had a large dent in the driver's side rear bumper.  Newtown Police were able to track down the other driver, who was cooperative and did not have a gun.  Spokesman Lt. Aaron Bahamonde says officers are conducting an investigation into the complaint and need help identifying the driver who initially called to complain.  Police are seeking further information from him and are not receiving the cooperation needed to conduct the investigation.