I wouldn’t follow the advice of your agent to tow the car on to the street otherwise you may find yourself subject to a fine by the council. I presume the car is an old one, and not likely to have been stolen. Even if it has plates I doubt whether the police would be interested in contacting the last owner, and they almost certainly wouldn’t get involved in removing it. It’s really a civil matter for you to deal with, if it’s in a parking space which forms part of your lot.
There are some interesting suggestions here:
Good luck!