When Stone opens the torn television guide sharp-eyed viewers will notice that his thumb rests on a capsule description of Young Man with a Horn (1950), a film that starred Kirk Douglas, father of Streets of San Francisco's co-star Michael Douglas.
On Robert Wagner's Jaguar the license plate reads "235 PCE". It is not a real California license plate as the lettering and texture look different. The "PCE" letters are seen on many TV and movie car licenses and appear to be as generic as the "555" phone prefix.
In the opening sequence, Stone and Keller "jump" a street hill in San Francisco with their 1971/1972 Ford LTD (similar to the classic scenes in the movie, "Bullitt"). Unless the suspension was reinforced, subjecting that Ford to that amount of stress would possibly bust the suspension, or otherwise severely damage the automobile.
At approximately 7:50 into the episode (as Robert Wagner enters and sits in his Jaguar), a cameraman is plainly visible in the chrome of the trim of the drivers side window. This goes on for approximately 20 seconds as Wagner sits and contemplates the police interview he had just finished.