Gangster-speak for a stolen hoop-dee; a stolen car. The "G" comes from "GTA", police acronym for "Grand Theft Auto". A "cold" G-Ride is an unreported stolen car. Widely mistaken by lame White Folk to mean an urban gangster's car, stolen or not. In an ironic twist, same term has been used for decades by Fed law enforcement Agents to describe the police-type cars they drive, plain or marked! (see next entry)
"Yo, MoFo, how we gonna git to da mall ta jack some 20's?"
"Chill, Niggah, I gots us a cold G-Ride!"