>>74058411) Junkions in terms of personality.
2) There’s an in-universe clown TV host, which the Junkions adore.
3) Cromar the Powerdasher kind of looks like a clown in robot mode.
4) Astrotrain and Blast-off have Mass Displacement-fu down beyond any clown car.
5) You could say any Transformer who turns into a vehicle used as a famous clown car qualifies. Many early uses of the clown car gag wasn’t painted, it was just an ordinary car that had all the internal parts stripped out to make room for clowns. Most were early Ford cars, famously the Model A. One early one was a washing machine on wheels modified to look like a car where the gimmick was one big clown. Mini Coopers, Fiats, and Volkswagen Beetles were also popular. The record holder is actually a Citroën. Transformer versions of these cars exist, sometimes just for commercials, but have no toys with the exception of course being Autobot Drones as VWs.