Mine is straight from the mani to the n1, its loud enough in the car although I've no rear interior a tall. outside it is loud but has a nice note to it, its also a bit to loud for doing long runs, it gets deafening and annoying to be honest. I then fitted a silencer which did silence it a bit but it still reads 113db
Thinking of leaving it then,'been offered a 2.5 inch unsilenced b pipe wonder how much it'd be to get a silencer or resonator put in, dno if its worth going custom