I don't live in an apt complex, but I live in town and have to park on the street. I live in a row house, and even though it's in the nice part of town, there are still about 20 kids on my block who play on the street and don't think twice before touching, leaning, running their bike into, or throwing something at my car. Apparently, the realtor payed them all to stay inside the day we looked at the house (I'm not serious, but I don't know where all these kids were that day). After two door scratches over a foot long from bike handlebars, one bike collision with the side door that left 3 dents, one scratch in the hood from a kid dragging a garbage can across the hood, and a big scuff mark on the door pillar from a football deflecting off the car... I had enough. I stood outside for a few hours on a saturday and told every kid that came near the car that I had cameras up and that I'd make their parents pay for any damage they caused to any cars on this street, especially mine. Then I pointed out that their parents wouldn't be happy about paying hundreds of dollars to fix my car and probably wouldn't let them play outside anymore. Then I told them to tell all their friends and parents. They responded pretty well to that. Now they all stay away from my cars, or their parents yell at them. They're all good people, they just didn't realize I liked my car and didn't want it scratched up.
I actually did put up cameras then... but not only because of the cars... someone keeps egging the houses on the street and I'd like to catch them and press charges. It's not because of me. A few of my neighbors are being discriminated against, and the discriminators have bad aim (or can't read house numbers).
Oh, and a car cover will help protect it, if you are willing to deal with the PITA of actually taking it on and off.
I actually tried parking down a few blocks where there are no houses and plenty of empty spaces, but there's a crazy lady there who keeps leaving notes on my car to "park your loud car in front of your own house or I'll report you to the police" and "ordinance requires parking between 3 and 6 inches from the curb, you are 7 inches, I reported you" and "A bird didn't do that". See, the first time I parked down there, the car got COVERED in bird s***. I was appalled. I couldn't understand how a bird did that. Apparently, she has a bird, and saved up the crap to dump on peoples cars who park near her house. Crazy doesn't begin to describe it. Now I deal with the kids on my block, rather than upset the crazy woman. Her husband screamed at me once for driving too slowly down the street, too. I thought he was going to walk in front of me, so I slowed down to let him cross. Then he just started flipping out.
I hate living in town.