The process of inserting your genetalia into one of the many holes of a hubcap that had fallen off a car. Usually done by mentally retarded persons who fantacize about having sex with their own cars. This is usally done to Subarus, Toyotas, Lincolns and Hyundais. Once the person has finished the action, they will usually ejaculate pre-maturely all over the curb infront of their home and run away. There have been over 384 cases of Hubcap sex reported in the year 2005, and the population is rising, we must prevent these repulsive and abusive activities done by elderly men.
Dude, I went outside to get the early newspaper and saw my neighbor Mr. Rogers engaging in Hubcap sex with my other neighbor's old 1998 Toyota Carolla Hubcap.