But you're talking of consequences to do with criminal acts. Parking in a private car park and breaking a contract ( even assuming the contract is valid ) is not criminal.
Taking it back to basics - under contract law a supplier can not penalise a private individual if that individual breaks the contract. All they can claim are losses to put them back to where they would have been if the contract hadn't been broken. So in a free car park, if someone over stays by 30 minutes what has the supplier lost ? Nothing or certainly not the £100 they generally ask for. To take your example of a full car park and so there being a possible loss of business - the supplier has to quantify what that loss would be and in that situation that is impossible. How would they know if the 'genuine' user will have brought something for a pound or a thousand pounds or even at all ? Even if they could, it's not the supplier that has lost out - it is the shop. Therefore the shop would have to take court action NOT the supplier of the parking 'management' service.
The private parking companies don't like contract law as it stands because their whole business model is built around people breaking the contract. What if nobody broke the contract and stuck to their made up rules ? They'd go bust very quickly. That highlights how false their business model really is.
