Palmer's car is actually at least two different cars - a 1966 MGB and a 1975 model. This is apparent in different scenes, where sometimes the car has side lamps and reverse lamps (1975) and sometimes it doesn't (1966), and where the interior changes between solid black with visible rectangular door pulls (1975) and black with red piping (1966).
The movie title is a reference to Sherman Way, a major east-west thoroughfare that runs the length of the San Fernando Valley in Los Angeles.