I feel for you bro, I have been monitoring your thread since you posted it up, firstly because I live down the road from you and work round the corner, secondly because I have a very loud exhaust and thirdly because I have been in a very similar predicament in Wymondham involving Norfolk Plod.
My sister-in-law is a trainee barrister in Norwich, and the advice she gave me was: although the police are NOT the law, they merely enforce the law but they can perceive the law differently to the actual law, and in almost all cases get away with it either way; because they make mistakes and are therefore responsible to their line manager, after the event. However if you drag matters through the courts, you could win or lose, but you could also be eligible to pay for the cost of doing so, either way.
In my case she said I had an extremely strong case to argue my innocence, but the shut up £65 fine and 3 points were not worth arguing about v the court costs if they came my way, no points but could have been a massive court fee, rather than £65.
In your case the £30 fine and no points could be a good thing, especially with the research you have conducted, £30 shut up I know, it’s the principal of the matter, same as me, and in hindsight I kinda wish I had dragged my innocence’s through the courts, rather than pay the shut up fee.
The police are not the LAW
The courts are the law, but you might have to pay for them and others to help you out.
I think Black Night has the answer, go to the magazines and papers, especially local ones (wish I had done this) to see if any will support you with legal aid, what the hell they get the scoop either way and pay for it.
Sunday, I walked the kids and dog down the end part of London road in Wymondham back home and a motorbike drove past 3 times with no exhaust, my 11 year daughter put her hands over her ears and screamed because it was soooooo loud, at a guess 140Db, figure that out!!
N