My advice: Just forget about the ticket and save your money. They might send you a letter and farm it out to a collection agency, who will phone you. If this happens, watch for and do the following:
(1) If they threaten to do anything other than take you to court, inform them that the attempt to induce payment with threats is extortion, and an offence under the Criminal Code. Also inform them that making threats, except for threatening to take you to court, constitutes the offence of harassment under s. 114 the Business Practices and Consumer Protection Act. A threat to ruin your credit rating qualifies as harassment.
(2) Tell them that you want them to communicate with you in writing only. They must obey this request under s. 116(4)(a) of the Business Practices and Consumer Protection Act.
(3) Tell them that the debt is in dispute and that you would like the alleged creditor to take the matter to court. After you request this, the collector cannot communicate with you, period.
You probably don't have to do number (3), since it not too much of a bother to just throw the letters out. Basically they can't do anything to make you pay until they've obtained a judgment in court. Even if they do have a valid cause of action (e.g., a contract), they can't use any coercive or confiscatory enforcement mechanisms until they obtain a judgment against you. The odds of them taking you to court are slim to none. It's not worth the $200 to pay a lawyer to go after a case they might lose. Their money is better spent harassing people who will get scared and pay. The only thing to worry about is racking up too many tickets. After a certain point, it makes economic sense to take you to court.
Until they take you to court, I don't think they can tow you from their lots unless you are over the time limit. The reason is that, absent a court order, any towing for the purpose of forcing recovery on past tickets is a seizure of personal property contrary to s. 122 of the Business Practices and Consumer Protection Act.
It's also doubtful that they can add collection charges to the stated ticket cost. Section 120(1) of the Business Practices and Consumer Protection Act prohibits a "collector" from collecting or attempting to collect money that exceeds the amount of the debt owing. "Collector" is defined as a person who is collecting or attempting to collect a debt.
I'm not certain what the limitation period for the action on the alleged debt is, but my sense is that it's two years from the date of the ticket, under s. 3(2)(b) of the Limitation Act as an action for trespass to property. If I'm wrong on this, the default limitation period of six years would apply. After that you can forget about the ticket, since any attempt to sue on it will be blocked by the Limitation Act.