Enemy gangs fight against each other. You can hear distant gunshots of enemy gangs fighting and you can tell by the way the crowds of people run away where the gunshots are coming from, it looks pretty cool in motion.
I really want to give impression of a chaotic environment once gunfire starts. I have a "cops" like camera shake as you run through the city, and the civilians/cops react to gunshots. News choppers circle areas of interest, you can view the action from the news chopper in a TV sort of presentation.
I still need to add some kind of visual indicator as to which direction gun fire is coming from, and there's a lot of polishing to be done.
The vehicle/traffic AI is pretty much done...they still have violent pileups every now and then, but they're pretty cool looking :-D I'm going to add a particle system for sparks, as well as full damage modeling on the vehicles.
The traffic resets pretty nicely after a pileup like the one below, once the player turns around and is a certain distance away, the cars resolve the traffic problem.