The front of the General Lee's fenders get visibly crumpled and dented when it hits the squad car, yet when it backs off again, the fenders are pristine.
The train that almost hits Boss Hogg is a Southern Pacific GS-4 Daylight steam engine. Southern Pacific never ran through Georgia. It ran through Southern California where the series was filmed.
At one point, when calling Rosco on his CB, Boss identifies himself as J.P. Hogg, instead of J.D. Hogg.