Part of driving on the roads today has to do with understanding the wide range of rules and regulations there are. Essentially from the perspective of a driver, it could be very expensive to have to pay for tickets do to a lack of knowledge of the rules. This might seem annoying but the fact it is that if you drive, you must be in compliance.
Luckily most of the new and used cars these days are built in a manner that makes it a whole lot easier to be in compliance with the stricter pollution laws. There was a time not too long ago when many owners would receive tickets because their vehicles were not up to the local codes. These days even the used cars under 5000 will probably have the correct exhaust systems installed from the factory. This will in the end save the driver on ticket expenses, but they still have to understand the important safety issues. This is typically taught in drivers education classes.