Our family was on vacation in Montreal. We had parked in an outdoor paid parking lot. It began to snow heavily. Upon leaving the parking lot the attendants swept off our entire minivan. They told us that we would get a ticket if our vehicle was not cleaned off. That should be a law in this state (country).
Once you think about it, cleaning snow off your vehicle so that snow does not blow off and cover someone else's windshield seems like common sense. During the recent snow I saw cars that only had cleared what the windshield wipers had pushed off. Those cars could only see what was directly in front of them, and they were leaving a trail of snow behind them for following cars to drive through.
Unfortunately, some people need to be threatened with punishment to get them to do the right thing. Violation of a snow removal law should have a greater fine than violation of a seat belt law. Not wearing a seat belt just endangers the person not wearing the seat belt. Not cleaning your car of snow endangers other cars on the road with you.