I agree with Slightly in that if you're not doing anything illegal, then you're fine. If you're breaking the law (a miss is as good as a mile), and you get penalized for it, you have no one to blame but yourself. Having said that, as Fivebob said, its a pity that its got to the point where the ambiguity around the "quotas" has left it looking very much like a revenue gathering exercise.
*shrug* maybe I've just been lucky to not get picked on, but in all the years I've been driving, the only times I've EVER been pulled over and fined is when I've done something stupid that deserved it. It may have been 60 in a 50 ... its still breaking the law. Who is to say when the line is "allowed" to be blurred between warning and penalty? Anyone who's been let off with a warning in the past should count themselves lucky. Driving is a privilege, not a right. Those who abuse the privilege should rightly lose that advantage.
To the original poster - have you taken into account the area you were pulled over? Is it not possible that the surroundings may have made your exhaust sound louder than it was to someone outside the vehicle? I'll be very interested to find out what the DB reading on your exhaust is when it gets tested, please post the results!
+1 for induction noise > exhaust noise
PS: Keep it friendly please everyone, this thread is getting some decent debate going, don't get it locked with outbursts and personal attacks.