Great point, and cities and states do have laws governing car emissions. If my car is too loud or emits to much pollution than the law can step in and correct this problem. I would have no problem if the community decided that my vehicle falls into this category and to act accordingly to correct the problem. If that happens I would abide by that law because I understand the reasoning behind it. I don't want someone to have to take a baseball bat to my vehicle to solve the problem. This isn't the "lowest common denominator" but the "highest common denominator." You cannot single out a specific person or family and then take action against them because you think their vehicle is the problem instead you must have a system of laws and ordinances that govern a class of people otherwise it is discrimination and is a violation of the rights of others.
That you would provide this example only proves how ignorant you are. I have no problem with people telling me that I cannot drive a certain type of vehicle or for that matter store junk cars in my yard. Do you realize that it is illegal in most communities for you to store junk cars that do not work and which are in bad conditions in your yard? Why? The idea of property values and the rights of others to have a clean neighborhood to enjoy.