The towed limo's rear leaf-spring gets broken when the car rolls up onto the curb after being released from Cooter's tow truck, yet when the mobsters pile into the car after discovering that the Dukes (and the stash of guns) are no longer in the rear seat, the car's suspension is fine.
When Bo and Luke are running from the mobsters, as they are jumping down onto Cooter's roof, Luke's shirt is different from the rest of the scene.
Obvious rear-projection screen used when the Dukes are fleeing the mercs' car in the General Lee --- the movements of the background landscape do not match the movements of the car, the cheesy-looking scenery is way off in the white-balance (excessive blue tone) and flashing brighter and dimmer, etc.