If you park your car in the wrong place,a traffic policeman

If you park your car in the wrong place,a traffic policeman will soon find it ,You will be very lucky if he lets you go without a ticket.However,this does not always happen.Traffic police are sometimes very polite.During a holiday in Sweden,I found this note on my car:"Sir,we welcome you to our city.This is a "No Parking"area.You will enjoy your stay here if you pay attention to our street signs.This note is only a reminder."If you receive a request like this,you can not fail to obey it.请帮我把这篇短文翻译一下