the short answer is i don't know
the story is yesterday (sunday) my girlfriend got pulled up by the cops. they asked her if there is an engineering cert for the exhaust - she said she didn't know. they asked her to pop up the bonnet and check out my enginer. i got no mods there so ok.
then she got the bloke to call me and he told me i needed to go to get an engineering cert for the exhaust (turbo back).
do i need one - whats a good way to tell the police i don't need one (if indeed i don't?)