A man found dead in his car in the middle of a Register-area peanut field Tuesday died of natural causes, said Bulloch County Coroner Jake Futch.Bulloch County sheriff’s deputies were called to Mike Brannen Road Tuesday after a man reported finding the victim, later identified as Billy Joe Rewis, 38, of Branch Wood Lane in Metter.The witness told Deputy Ross Newman that he was traveling down Mike Brannen Road around 4:30 p.m. when he saw a white Mitsubishi at the edge of a peanut field. The first time he drove past, he didn’t notice anyone with the vehicle, but when he returned 10 minutes later, he saw the driver “slumped over” the steering wheel.The witness found Rewis not breathing, shut the car off and called 911, reports said.Tracy Nesmith, a first responder with Bulloch County EMS, also responded to the scene and determined Rewis appeared to be deceased, according to sheriff’s reports.Futch said it appears that Rewis experienced a “massive myocardial infarction,” or heart attack.