fromthe OP then, can they not call the cops on the guys, given he says how they seem to park in away that block others in?No. It is an offence to clamp cars regardless of charge. It is an offence to clamp, tow, block-in or immobilise a vehicle without lawful authority on private land under the Protection of Freedoms Act 2012.
anyways, maybe a simple solution would be a simple set of posts hammered into the ground w/ a length of chain across?