Hi m8, the same thing happend to me, was fined 30 quid by traffic cops for having an illegal back box and to noisey they said, its a hayward and scott jap spec one, I wrote a letter to the inspector of the road policing unit and stated that my exhaust was not illegal, it was not to loud to break any local bylaws with regards to noise as i have an email from hayward and scott to comfirm this, and also that the police did not have any tecnical data for my car as standard and neither did they test it scientifically with a decebell meter as it is now to compare it to standard, also when tested with a decebell meter it has to be done in a contriolled environment with a specific set of procedures, which they could not do at the side of the road.
my car is alsoa jap imort i poined out to them so optaining data for them will be difficult ye ha, the inspector scrapped my 28 day to pay ticket and sent me a letter saying he was prepared to let it go,
Why you may ask, becouse i had them on this one, long live the flat 4 burrble
ps soz about the spelling