The "Inverted Triple Needham" refers to Hal Needham, a stuntman and the director of Smokey and the Bandit (1977), specifically to what Needham himself referred to as the worst car accident he had ever been in. Occurring during the filming of John Wayne's McQ (1974), Needham broke his back, six ribs, punctured a lung, and lost some teeth.
Pam is wearing a Poovey Farms Racing cap.
Pam's CB handle "Snowball" is a reference to oral sex, as described (quite graphically) in the Kevin Smith film Clerks (1994).