Ecto-Junior is a small go-kart that fires pumpkins and plungers, but isn't very useful against ghosts due to its lack of ghostbusting equipment. When not in use, Ecto-Junior is stored in Jason's mother's garage. During one Halloween, the Junior Ghostbusters used Ecto-Junior to perform reconnaissance on Samhain's Fortress but they were pursued by two Goblins. Donald launched a pumpkin and dispatched the Goblins but Samhain and his army surrounded Ecto-Junior.
- According to writers Pamela Hickey and Dennys McCoy, in the "Halloween II 1/2" visual commentary, there was a network directive that stressed Ecto-Junior had to appear to have been constructed with glue and PVC pipes but not hammers and nails, in case children tried to imitate and create their own Ecto-Junior vehicle. 
- Writers Pamela Hickey and Dennys McCoy take credit for creating Ecto-Junior for the show. They both came from the Midwest, where go-karts were considered cool. 
- The Sleaze used the Ecto-Junior's giant rubber band to launch himself out of the City Dump.
- On page 10 of Ghostbusters Issue #8, Ecto-Junior makes a non-canon cameo across the street from Delgado's Gym.
- Kaufman, Charles, Janson, Len & Menville, Chuck (1988). Slimer! Series Bible (Revised Final 3/9/88)" Script p. 16. DIC Enterprises, Inc. Paragraph Reads: "They idolize the Ghostbusters and emulate their heroes in many ways, even driving a homemade go-cart they call "Ecto Junior", that's outfitted with crude kid-versions of ghostbusting gear."
- Pamela Hickey and Dennys McCoy (2009).The Real Ghostbusters- "Halloween II 1/2" (1987) Visual Commentary (DVD ts. 11:12-13:00). Time Life Entertainment.
- Pamela Hickey and Dennys McCoy (2009).The Real Ghostbusters- "Halloween II 1/2 " (1987) Visual Commentary (DVD ts. 11:12-13:00). Time Life Entertainment.