Mitchell went on to also sell Rolls Royce cars and later moved out of downtown to the Buckhead area of Atlanta I believe.
Screenshot from a first-season (1967-1968) episode of the TV show Mannix. Note the two dealership signs on the right side, Brucks Oldsmobile and Cort Fox Ford. Neither dealership is still in business. There's a Chrysler dealership further in the distance on that side, but we can't make out the name. You can see the pentastar logo. The view is through the windshield of Mannix's modified 1967 Olds Toronado, and he's tailing the taxi ahead. Brucks Oldsmobile was at 4575 Hollywood Boulevard. Here's an ad for it from the May 20, 1954 Los Angeles Times. The dealership opened in 1952 and closed in 1980. Here's a modern-day google street view of that same location and in the same direction, as near as I can get it. There's nothing in the 1967 photo that survives 50 years later except the profile of the mountain range on the right side and the red building on the left side of the road just left of center in the distance. Here's a closer-up view of that building from the Mannix photo. In the Mannix photo, the building is light gray with blue trim. Note that the corner of the building just above the white van is angled 45 degrees to the two sides. Here's that same building from the google street view. I moved up the street so we can get a better view of it. It has the same angled corner.
Hollywood Boulevard looks totally deserted. Last time I was on it, in the late Eighties, the midweek traffic was like Sunset Boulevard on a Saturday night. Not to mention, the air looks cleaner.
The local Dodge dealer took great pains when they moved to then-new digs in town, to remove their neon 'DODGE' signs and install them, then get the electricals worked on to restore them to their flash sequence.