The location used as Gail's apartment (5-7 Minetta Lane according to movie-locations.com) is the same building used to represent Frank Serpico's apartment in that other famous Pacino film. Minetta Lane in Greenwich Village is used often in films, TV and commercials because it is only one block long, with a bend in it. Both ends of the street can easily be blocked off for filming.
The several minute steadicam shot in the railway station was initially meant to end with it revealing Al Pacino. They only had one chance to make the shot work due to scheduling and the lengthy time it would take to reset. The shot went just as they wanted except at the very end when a miscue between the AD and the steadicam operator resulted in him panning to Pacino before he was ready. As such, the shot didn't end the way they wanted, so they filmed a cutaway to another character and then revealed Pacino in another shot.
A sign that reads "242nd Street Bronx/South Ferry Manhattan" is visible on the subway car when Carlito heads to Grand Central station. The sign indicates that he is on is the 1 line which does not go to Grand Central.
When Carlito goes to visit Kleinfeld in the hospital, the guard in the hallway is holding a newspaper with both hands. When the camera changes angles, the guard is holding the paper with one hand and pointing at Carlito with the other hand.
There is a line you cross, you don't never come back from. Point of no return. Dave crossed it. I'm here with him. That's means I am going along for the ride. The whole ride. All the way to the end of the line, wherever that is.
Why Did Saso Steal Carlito's $70,000 Dollars Out of The Safe?
Saso took Carlito's money because he had heard the Italians had killed, or tried to kill, the
double crossing, crooked lawyer David Kleinfeld. So Saso figured they were going to catch up with Carlito and kill him next.
So he just took the money for himself not expecting to ever see Carlito alive again.