Pontiac Firebird was a "muscle car" produced by Pontiac in the late 20th century.
As Admiral James T. Kirk's group walked down Kearny Avenue, one of these cars was traveling southbound on Columbus Avenue. The car was equipped with removable roof panels. Sometime in its past the car had been damaged on its rear left side, as a large dent was visible on the car's body. (Star Trek IV: The Voyage Home)