I have a Yoshi exhaust on my CBR600F4i - I would love to claim it is for safety reasons, but honestly I just love the sound it makes On bikes if you buy an aftermarket exhaust you have to stick a little metal plate on the muffler and have it engraved stating it is legal to the dB limit, no sticker = trouble, but even if you have the sticker they can still test you As for the cops being too scared to pull over Harley riders - I don't think so - most are accountants under the helmets (obviously not talking about gangs here) It's just one of those things I think, Harleys are regarded as having there own unique sound (straight from the factory), whilst the cops pick on sports bikes *shrug* for aftermarket cans. Harleys are definatley not my cup of tea but each to their own. As for the centre muffler, yes its illegal, but I seriously doubt anyone would pick it unless it went over the pits.