The film was based off a script that was set to be a sequel for Leon: The Professional. The story was set to follow Natalie Portman's character Mathilda as she tracked down and killed characters that had wronged her and Leon. Portman's success kept her from availability and the script was eventually re-written into the 2011 film Colombiana.
The memory card being used at the beginning of the movie, which the young Colombiana swallows then vomits up, is a SmartMedia card, manufactured by Toshiba in 1995. When the agent is wiping it off, you can see the silver circle under his thumb. This was the write protect sticker. He then puts it in a floppy adapter which made it readable by any PC with a 3.5" floppy drive.
In the scene where Cataleya rams into the police car, it is in a place outside New Orleans called Fat City. The bar Uncle Larry's, was actually a real bar at the time but is no longer there. Also in the scene, briefly, you can see a sign for Circle K and a split second later you see Brother's; it's actually the same building. The gas station was under construction during filming and Brother's had bought the Circle K franchise.