That information I got direct from several troopers in the Tennessee Highway Patrol. Also got info from Bill Reynolds of Knoxville, who is the proud owner of a '59 Chevy THP car (all original). He knows quite a bit about the history of THP and had several family members who were troopers.
As far as hot-rodding the car, I know Tennessee Highway Patrol used to alter the cars or the district captains. Traditionally, the Captain was always given the fastest car in the district. Either a better production model car with a bigger engine than the road troopers or the engine modified...