I would approach the management first.They would have to know this shit is happening in their carpark,some duty of care needs to be taken on their behalf.
and if you need to park you car there or any car park get an alarm or kill switch so these f**kers can not take it.
the only place my car is parked is in my garage,i dont even park it in the driveway.Call me paranoid,but atleast i still have my car.
Another thing,these cars are obviously sought after,might be an idea to buy a run around car for a daily driver as i have done,and i know many other members who have done the same.