An argument over whether Fords or Chevys are better vehicles is behind an alleged stabbing incident in Georgia.   The "Calhoun Times"  is reporting that several people were driving off-road vehicles in a field when an argument escalated into a fist fight early last Saturday morning.  Witnesses say the fight over the superiority of Fords versus Chevys ended when Zachary Woody of Calhoun allegedly pulled a knife and stabbed the unidentified man.  Woody has been charged with aggravated assault.