Ok! Slipped it on and I must say didn't notice any difference really whilst stationery! So took her for a run, that's when you hear it, it's subtle just a deeper sound really, not as ear catching as the preds on Doris but I wasn't after that. I quite like it. Maybe it sounds louder from behind( ooooer) maybe I'll have a go at knocking one out later. But will I need to remap if I do? Fuel consumption seemed s bit down on the normal can. All in all I like it and maybe it could do with a hole or two drilled in the baffle. Oh and it's at least half the weight