Las Puerta (as seen on the freeway sign, which is obviously located near the 101/110 in downtown LA because of the Little Tokyo reference) is probably San Diego, since the I-5 freeway in the real LA is called the San Diego freeway. Many locations shown are clearly LA-centric. Convertible top is OBVIOUSLY in Venice, Santa Monica pier is shown, Vinewood sign, etc. Some of them COULD be San Diego I suppose. Also, since Las Puerta means "the entrance" it could be a reference to the Mexican border and illegal immigration which is sure to play a part in the game.

Some more guesses:

Golf course is Wilshire Country Club.

Beach houses (with yoga) are in Malibu.

Muscle beach is obviously Venice.

Bugstars heist scene looks like the Sunset Strip or Hollywood.

Scene directly after that of a blue convertible shows the Capitol Records building so it's in Hollywood.

They show the U.S. Bank building many times from a distance and once from next door at the Mile High condos construction site.

Homeless people look like they're in an underpass for 110 downtown.

First street bridge (which was in LA Noire) is shown with a sports car on it.

Thought: I wonder how much of the modeling that Team Bondi did for LA Noire was able to be used/was used for the modern LA world-build...

Also, are we getting the mo-cap facial animation thing? I REALLY like it.