The 1963 Cadillac parked in front of the police station shows to be a bluish gray colored "6 window" model. Short time later in front of the high-end restaurant shows a 1963 blue colored "4 window" model. Same vehicle body style is shown later in front of Kenny's Cookin' restaurant and leaving after shooting at Bubba. At the end when Ken is arrested, the "6 window" model is shown.
The establishing shots of Gulfport, MS were actually filmed in Long Beach, CA. Oddly enough, Gulfport's neighbor to the west is Long Beach, MS.