You mentioned your complex was gated...they had to get in somehow. Maybe a friend of someone that lives there? Do you have a guard there at night to let visitors in? If so I would let the guards know about it and give them a description of the car. They might have seen it come in...and if there are cameras gotten a license plate number. Let them know too that you and only you are leaving in your car...give them your description of the car and unless you call ahead they should assume the car is stolen. Also you might need to register your cars with the condo/apartment management company. Give them the description of the thieves car and see what comes up.

Also invest in as many anti theft devices as you can. Make sure your alarm has a backup battery and airhorns...those suckers are loud. Also invest in a club for both your stearing wheel and brake. They will not want to try and get those off if the airhorns are going and they cannot shot them off...so make sure you get them mounted in a place that is not convenient to tamper with them.