Truck Nutz, Bulls Balls Truck Nuts, Eggs for Hitch, Big Eggs on the Car | eBay
Eggs Hanging Ballz Truck Nutz Bumper Balls Bull Nuts for 1/10 1/8 Model RC Car | eBay
Bulls Balls
Crooked Lullabies: Product Review: Bumper Balls
Amazon.com: United Pacific 70144 8.25” Tall Large Low-Hanging Rubber Bull Balls, Injection Molded Rubber, Perfect for Trailer Hitches/Bumpers - Blue - One Unit : Automotive
Why do people hang ornamental testicles on the back of their trucks? - Quora