Also take into account gents, it is becoming increasingly common for insurance companys not to pay out after an accident/incident if they can prove that a race can was fitted at the time of the accident/incident. Remember when filling out your insurance renewal the question that says something like ' has the vehicle been modified in any way'.
My insurance documents actually state that my insurance will be void if a non-approved exhaust system is fitted. When i rang them to clarify the situation i was told the exhaust must be BS stamped.