Nah Al, I'm only pulling your leg mate...
John, thats a very interesting thread, with, a very interesting link too, the five-0 forums, where there was a couple of bobbies that clearly dont know any better about the law...
opens the eyes a little...
Personally I would make a point at the time of making a statement that you were not happy with the test, that it was not carried out within regulations... they have to write that down in their little books, word for word, and that then is evidence... because you are making a statement... but yeah, better safe than sorry, at least then if they try to convict you, from the word go there is a challenge...
But the bottim line here, I think, is that if the exhaust has a Kite mark, or an E number, is in good condition, is not modified (ie: its not been cut) then really, its legal... so yeah...