A slang term for a custom car in NASCAR The Game 2011. Infamously, no one wants to race with one of these due to the massive lag they cause. Because no other players can see custom cars in a race, they are instead shown as a yellow #53, hence their name.
Player 1: (Dissapointed): Shit, look at all these fuckin' 53s in here.
Player 2: Yeah, man, we're screwed. This race is gonna lag like hell. I'm dashboarding it now and savin' myself the trouble.