On a road trip through the western desert to see Dexter's grandfather (who is unwell and wears a little cardboard hat), the Douglases encounter some speed-demon sentient crash test dummies in hot rods who run them off the road. While his family is stranded in the desert, Dexter "freaks out" and uncovers a fiendish plot by supervillain Longhorn, who plans to steal a nuclear warhead being transported by the U.S. Air Force, in order to hold Nashville hostage until he is given a recording contract. Freak gets his favorite Freakmobile ("because it runs!"), and engages in a high-speed chase across land, sea and air.
- Sergeant Mike Cosgrove
- Debbie Douglas
- Dexter Douglas
- Douglas Douglas
- Duncan Douglas
- Paul Harvey
- Emmitt Nervend (poaching eggs in bird's nest)
- The actors credited as appearing in Hot Rods from Heck! are: Ruth Canto, Mimsy Ling and Weena Mercator as the Hopping Woman; the "film" is directed by Dobie Atwood Jr..
- The geography of this episode is particularly absurdist: although the majority of the action appears to take place in the western U.S., Freakazoid manages to go to his Freakalair (in D.C.), then returns to the western desert via a Freakalair exit specifically built to connect with that location. He then uses the Freakmobile to grab a piece of the Great Wall of China, and lures Longhorn to Wrigley Field in Chicago, Illinois (with Freak on foot while Longhorn is in his truck).