Step 1: Do not damage the vehicle, otherwise it will be considered vandalism etc. (However justified)
Step 2: Make sure that all complaints/requests to the Body-Corporate are in writing
Step 3: Approach the Ombudsman if the BC is not acting
The BC should essentially send all the residents a notice requesting to come forward if it is theirs or their visitors, after a few of these, they can legally remove the vehicle.
The BC should then pay for the towing, and try to recover the cost, if not possible to recover, then just write it off as part of their mandate.