The Cadillac Escalade was the first car Tallahassee drove in the movie. The Escalade was black and had a white "3" drawn on its doors, and a snowplow-style attachment on the front.
After Tallahassee and Columbus met Little Rock and Wichita in the store, the girls tricked the boys into handing over their weapons by pretending that Little Rock was infected by the disease, thereafter the two girls stole the car.
Later, the girls abandon it as it overheated. They take the Hummer H2, which the guys were using at that point.