Top definition. Truck Nuts unknown. A pair of testicles attached to the rear of a car or truck used as an international symbol allowing homosexual men to identify each other. Red or blue colors are used to indicate if the vehicle owner is a "top" or a "bottom" while other colors indicate "no preference" as well as usual, or unusual preferences. Size of the nuts have no direct relationship to the actual size of the owner's penis and are usually misleading. Ricky's heading down to the strip to scope out some truck nuts.
The Original Bulls Nuts, Truck Nuts and Bulls Balls – torontotransalliance.com
Truck nuts , also called truck nutz , are vehicular vanity accessories resembling a dangling scrotum. The "truck nuts" phenomenon existed in small numbers as custom-made scrotum sacks beginning in the s. The earliest known commercial store-bought truck nuts appeared in the late s but still remained a limited phenomenon. A number of people claim to have invented the truck nuts industry i. David Ham,  owner of YourNutz. John D.