I got a parking ticket 3 weeks ago, but no letter from the police. While doing some research I found this little scam:
A dude got some tickets, he scanned them, removed the data, but kept the ticket number, then changed date and location and put it on an illegally parked car nearby. Idea was that the driver goes to the next 7Eleven or whatever place they can pay and simply pay the fine.
BTW, after talking to the police they told me that they send only a letter if people don't pay, so quick pay, no letter.
Salesman 'printed fake tickets to pass on Hong Kong parking fines to unsuspecting motorists' | South China Morning Post