We have a lot of speed enforcement and red light cameras here. Now, I don't approve at all of the relentless lowering of speed limits and their ruthless enforcement, it's an absolute offence, but if the limit is 70 and you're doing 71, you're speeding and bang to rights. Whether or not the limit should be 70 or not is another debate, it's 70, you're doing 71 and have broken the law.

I keep banging on about it, but a lot on here lead fairly sheltered lives and have no idea how a lot of people live. Dirty air is miserable and laws have been brought in to clean it up. If you are modifying you vehicle to circumvent those laws you are breaking the law, so why should you get away with it when others are obeying the law and keeping their vehicles maintained and clean? It will be quite easy to know what each vehicle is allowed to have in their exhaust by looking at the VIN, which is linked to the registration plate on the back and front of the vehicle, mine is Euro 5 (I think), and the spec for Euro 5 is what ever it is. If the emissions exceed them on the roadside tests, you get pulled over and have some questions to answer