The diner seen here, The Saugus Cafe, is still in existence at the same address - 25861 Railroad Ave, Santa Clarita, California. The address is seen on the building. It can been seen in the Google Streetview. Apparently the street has been widened, as the parking lot is now gone, and the sidewalk is now up against the building. The barber shop is gone, replaced by a parking on the side.
Victim Frank Douglas is driving a 1952 Ford Crestline Convertible when he is stopped by the Highway Patrol. The Cestline featured a 239 cu.in. Flathead V8 engine rated at 110hp and a Ford-O-Matic transmission. The Convertible Louise Douglas steals at the restaurant is a 1955 Mercury Montclair Convertible. As was common with many vehicles of the 1950's, the Montclair did not have a side mirror mounted on the driver door. Dual side mounted spotlights with integrated rearview mirrors were an option.