Rachel.
1. Look into the ownership of the land. They are jews.
2. Whether they are jews or not, is irrelevent in that they don’t want tashlich parkers using their lot. Whether their reasons are valid or purely hateful, doesn’t matter. If they choose to enforce it in such a sleazy manner and someone decides to risk it anyway, that’s a risk they are willing to take, and if they lose, they can’t call out the towing company/landlord.
3. If you really believe there are nefarious shenanigans going on, call any of the local TV stations and have them air a “shame on you segment” on these guys and their practices.