This one has been languishing for a while, so let's try to get started on it.
Is this a particular event that we need to identify? I don't know what it is, but to get things rolling:
What? - I'm not very good on American cars, old or new, but the oldtimer is a Cadillac (and I'm sure there are no prizes for guessing that!). I think it's a Model K, and if that's right, then I also think it's a 1907 model, and not a 1906, by the shape of the front wings.
Where? - My guess is Hollywood, California, where Clarence Dixon was a well-known Cadillac dealership on North Vine Street. But this is not the front of the dealership, which would have been glass-fronted showrooms. This is obviously the servicing department, so round the back of the building, or the side? Or maybe somewhere else completely?
When? - I'd guess 1958, solely on the basis that Hollywood residents probably wouldn't want to be seen in last year's model of car, and (again unless I'm mistaken), that's a '58 Lincoln Continental behind the Cadillac.
That's as far as I've got, and having tackled a few of Monsieur Ray's puzzles before, I'm fairly sure that the answer to this is more than just the sum of its parts.
So is that any kind of a start?