The Shitmobile is Ricky's ramshackle 1975 Chrysler New Yorker. It initially belonged to Julian, who inherited it from his late grandmother. After their return to Sunnyvale in Episode 1, Julian let Ricky live in the car for a while and ultimately gave it to him in the next episode.
The car owes its inglorious name to its deplorable condition caused mostly by Julian's grandma's reckless driving (especially while intoxicated). Its most notable trait is the lack of the right front door, which was lost during the Christmas Eve 1997. In between Seasons 3 and 4, during his tenure as the Sunnyvale Trailer Park Supervisor Ricky took out the right door from Lahey's car to fill the gap, but gave it back when Jim became the supervisor once again. The Shitmobile is actually green, however it was recolored black with a very poor-quality paint which tends to easily come off, revealing the true coating. The car's transmission does not operate according to design: according to Ricky, the third gear is normally used for driving, as the "drive" gear causes the car to go in reverse, neutral parks the car, while reverse puts it in second gear. The drivers' side door does not open, thus Ricky enters and leaves the car through the hollow right side.
Since it was used as Ricky's 'home' most of the time, he used it for almost all house-related purposes, including sleeping, banging, a cooking surface, growing dope in, and even showering. Typically, when not in motion, the Shitmobile is littered with all manner of personal effects and debris, which is later cleared off with the 'clearing stick' when it is needed for travel.
Tom Arnold drove the Shitmobile to cross it off his Bucket List.
In Season 12 it is the foundation of Rickys Carhouse with upstairs urinal and a bit of a bar. "Where In The Fuck Is Randy's Barbeque?"