Cletus's hat flying up and back down when he sniffs the villainous brew that J.D. had concocted is an obvious nod to Stan Laurel, whose hat would always fly upward whenever he would sniff some strong-smelling bottle of liquid.
Daisy again drives a yellow Plymouth Roadrunner during her races in this episode --- an obvious nod to her previous beloved vehicle-of-choice before the Duke boys unintentionally demolished it and she got Dixie instead.