[WS:] That is very simple, actually. Put the cap on what the towing company can charge for towing. As I understand it, they can charge whatever they want, which often is several times the regular towing rate, which creates a financial incentives for these guys to bend if not break the law to tow your car.
Another thing - require a positive proof (photos, witnesses, etc.) that the car was parked illegally - not just the word of a jackass with a tow truck who has a financial incentive to hijack your car.
I am not against the principle of towing illegally parked cars - I am against turning that into a money making racket by unscrupuloos business scum.
Wojtek