Sorry to hear about your plight seeformiles

maybe the only solution is for residents parking permits, yet that would not work in a private car park, do you live in flat, if yes, then maybe you should ask the landlords who own the freehold to put up notices that state you will be clamped if you park here illegally

It worked for my friend when they lived in Colliers Wood, other thing they did was to park right in front of one the offending cars, so they were blocked in, maybe not such a bright idea in this day & age as who knows what will happen to you/your car