Upstairs neighbor's stuff on my patio?

The apartment management should not be blowing you off like this. Tell them you want something done about it or you will have no choice but to call the police to see if harassment charges can be filed (and then call to see if they can be). Call management each and every time something like the trash is on your patio or something is obstructing your car. Tell them that you want the issue resolved, period. The glass and trash in the parking lot is a hazard for EVERYONE as are the falling objects on your patio. Tell management that they will be held responsible should someone get hurt (by falling objects or tripping on an item thrown on your patio) or damage is done to someone's property (parking lot, trash on patio, etc.) due to their failure to address the issue with the neighbor.