Should people be free to pollute the atmosphere at will? 
Of course not, air will continue to remain a common interest, no matter how well private property rights enter into division of land, water rights, even airspace, we all continue to breathe the same air.
This is one reason the communist/socialist proponents have latched-on to environmental issues, shedding their red flags for green ones, and why they cling so religiously to faulty junk science when it concerns the atmosphere, i.e., ozone holes and human-induced global warming; because this really is something that needs a tiny bit of governmental oversight, at times, and even international cooperation, so they run with it all the way.
More to the point, though. The problem I see with current motor vehicle emission inspections and other such regulations is that they cause a lot of harm and misery to everyone yet do very little to actually control the worst polluters.
For instance, last year I sold a newer economy car with only 8,000 miles on it, yet I still had to take two hours out of my busy schedule and go down and pay $45 to get an emission inspection on it. Needless to say, the car easily passed and the inspection station got their money, though they left grimey hand prints all over the steering wheel, and the state got some more revenue out of that on top of the sales tax and hefty registration already claimed only a few months earlier when I bought the car.
Then I have heard the sad stories of people who get various components of their emission systems damaged by the test, even cases of getting their car totaled when the car slips off the treadmill at 45 miles an hour. Then there are alwys numerous stories of abuse, the little old grandma that takes her 5-year old Oldsmobile and is told she has to spend $900 or get her car impounded for not passing inspection, and forced to pay or walk home. Then there are the numerous stories of people who adjust their carburetors to run thin for inspection then tune them back to thick after passing the 'smog test'.
All this, and the fact remains that 3% of the vehicles out there are still contributing more than 40% of the pollution, even with inspections. Daily I encounter cars spewing clouds of thick dark , smelly smoke that somehow passed the last smog inspection.
Once I spoke with an engineer who is also a car enthusiast, who explained one of the pipes on an emission system is actually an intake for fresh air to dilute the emission system so that it better passes government inspections. It actually makes the car less efficient in both catalytic exchange and in robbing the car of power, yet the diluted exhaust came up better in the measurements, which pleased the bureaucrats so it remained on millions of cars for several years.
In my opinion, the best way to end car pollution is to end all this sensless spending on things that don't really work, that only please a few busy-bodies and just allow people to spend more of their transportation dollars on efficiency-improving technology. Maybe there is some justification to setting-up 'sniffer' machines along the roadway and nabbing the bad polluting cars on the road by sending the car owner a bill in the mail, such as has been implemented in some parts of the country. But I think that having everyone carry-on this yearly emission inspection routine is just ridiculous and does little to actually catch the few polluting cars.
